root of _Cissampelos pareira_” (Ph. L.), white pareira or velvet leaf. It
is tonic, aperient, and diuretic.——_Dose_, 20 to 60 grains; in chronic and
purulent inflammation and extreme irritability of the bladder; in
leucorrhœa, dropsy, ulceration of the kidney, &c.
=VENESECTION.= The practice of venesection, bloodletting, or phlebotomy,
as it is variously denominated, has within the last thirty or forty years
been nearly banished from medical practice. It seems very evident that
prior to the above period medical practitioners were in the habit of
resorting to venesection to an unwise extent, and in cases which the
progress of modern pathology has shown it to be wholly inapplicable.
There are, we believe, some practitioners who, whilst admitting the evils
arising from its misapplication and abuse, still advocate its occasional
and judicious employment.
Because of the dangers that beset the operation when performed by a tyro,
we forbear to give any particulars as to the method of carrying it out.
The veins of the arm are those always invariably opened in venesection,
although the operation may be performed on many other superficial veins.
=VEN′ISON.= The flesh of several species of deer. That from good land,
killed at the proper season, and eaten in a moderately fresh state, is
most easily digestible, and, perhaps, the most wholesome, of all the red
meats; but when it is ‘high,’ or in a state of incipient putrefaction, it
is far from wholesome, and often poisonous.
=VENO BENO (La).= See TEA.
=VENOM.= Drs Brunton and Fayrer, who have devoted many years to the study
of the nature and physiological action of snake poisons, state that there
appears to be some resemblance in the action of the venom or virus of the
cobra, _Naja tripudians_, and of curara, the arrow-poison of the Indians;
both poisons causing death by paralysing the respiratory organs.
Dr Armstrong, who has analysed the cobra poison, has not been enabled to
isolate from it any crystalline principle. From its reactions he concludes
that its chief ingredient is an albuminoid substance.
Dr Armstrong obtained a white precipitate from the poison by treating it
with absolute alcohol, and also prepared an alcoholic extract from it.
He gives the following as the composition of the three substances. The
albumen is appended for comparison:——
Crude Alcoholic Alcoholic Albumen.
Poison. Precipitate. extract.
Carbon 43·55 45·76 43·04 53·5
Nitrogen 43·30 14·30 12·45 15·7
Hydrogen ... 6·60 7·00 7·1
Sulphur ... 2·50 ... ...
Ash ... Traces.
“But although there is little difference between the composition of the
alcoholic precipitate and extract, there is an immense difference between
their physiological action, the extract being a virulent poison, the
precipitate almost inert. This is notably different from what has been
stated by Dr Weir Mitchell respecting the poison of the rattlesnake, viz.,
that the alcoholic precipitate is active, whilst the extract is
inert.”[255]
[Footnote 255: “Royal Society’s Proceedings,” ‘Pharm. Journ.’]
=VENTILA′TION.= The proper ventilation of our habitations, as well as of
other buildings in which we pass any considerable portion of our time, is
quite as necessary to health as food and clothing. Lavoisier, writing in
the middle of the last century, remarks——“It is certain that mankind
degenerate when employed in sedentary manufactures, or living in crowded
houses, or in the narrow lanes of large cities; whereas they improve in
their nature and constitution in most of the country labours which are
carried on in the open air.” Yet many persons, by the care which they take
to shut out fresh air, and to prevent the escape of that which their own
bodies, by pulmonary and surfacial respiration, have contaminated, would
seem to hug to themselves the discomfort of breathing over and over again
an impure and unrefreshing atmosphere, and to be anxious to finish their
career by lingering suicide. The almost universal indifference to the
subject, considering its importance, is unaccountable.
The first step towards effecting and maintaining a liberal supply of fresh
air is either by means of ventilators or by regularly opening the windows
for stated periods daily. During the colder portions of the year, when
fires are kept burning, and there is an up-current in the chimney, nothing
is so simple and effective as the well-known chimney-valve of Dr Arnott;
and, indeed, without this, open fires are powerful instruments of
ventilation. In cold weather, where expense is not an object, the
apartments may be supplied with air that has been previously warmed by
passing through a heated chamber, on the principle recommended by Dr Reid;
but care must be taken that, in warming the air, we do not overheat it,
nor contaminate it.
A sufficient supply of light, another powerful sanitary agent, is now
regarded as nearly as essential as thorough ventilation, and the two are
commonly treated of together. According to Palladio, the opening of
windows should not exceed a fourth, nor be less than a fifth, of the
length of the side of a room, and should be in height two and one sixth
times the width. Mr Gwilt, another high authority on this subject, has
given as a definite rule, that we should allow 1 square foot of glass to
every 100 cubic feet of space in any apartment or inclosure. A great deal
must, however, depend on the shape of the apartment; but, in all cases,
care should be taken that the windows are placed at the longest side of
the room, and not at the narrowest, or the end of it. A southern aspect
affords the most light and heat; a northern one the most diffused and
least variable light, and is hence usually chosen by artists for their
studios.
=VERA′TRINE.= C_{32}H_{52}N_{2}O_{8} _Syn._ VERATRIA, VERATRINA,
SABADILLINE; VERATRIA (B. P., Ph. L., & E.), L. An alkaloid discovered by
Pelletier and Caventou, in the seeds of _Asagreæ officinalis_ (sabadilla),
and in the rhizomes of _Veratrum album_ (white hellebore).
_Prep._ 1. (Ph. E.) Digest sabadilla seeds in boiling water for 24 hours,
then squeeze them, dry them thoroughly by a gentle heat, beat them in a
mortar, and separate the seeds from the capsules by agitation in a deep
and narrow vessel; next grind the seeds in a coffee-mill, and exhaust them
by percolation with rectified spirit; concentrate the resulting tincture
by distillation, so long as no deposit forms, and pour the residuum,
whilst still hot, into 12 times its volume of cold water; then filter
through calico, and wash the residuum on the filter as long as the
washings yield a precipitate with ammonia; unite the filtered liquid with
the washings, add ammonia in excess, collect the precipitate on a filter,
wash it slightly with cold water, and dry it first by imbibition with
filtering paper, and then in the vapour bath. “The product is not pure,
but sufficiently so for medical use. From this coloured substance it may
be obtained white, but at considerable loss, by solution in very weak
hydrochloric acid, decolorisation with animal charcoal, and
reprecipitation with ammonia.”
2. (Ph. L. 1836.) This is the same in principle as the last; a tincture is
formed by boiling the seeds in rectified spirit, which is then evaporated
to a syrup, dissolved in very dilute sulphuric acid, the veratrine
precipitated with, magnesia, redissolved in very dilute acid, treated
with animal charcoal, the filtrate again evaporated to a syrup, and
precipitated with ammonia; it is, lastly, washed and dried.
3. By means of ether, as noticed under ALKALOID and ACONITINE. This is by
far the best method.
4. (B. P.) Cevadilla, 2 lbs.; distilled water, q. s.; rectified spirit,
q. s.; solution of ammonia, q. s.; hydrochloric acid, q. s.; purified
animal charcoal, 60 gr. Macerate the cevadilla with half its weight of
boiling distilled water in a covered vessel for 24 hours. Remove the
cevadilla, squeeze it, and dry it thoroughly with a gentle heat. Beat it
now in a mortar and separate the seeds from the capsules by brisk
agitation in a deep narrow vessel, or by winnowing it gently on a table
with a sheet of paper.
Grind the seeds in a coffee mill, and form them into a thick paste with
rectified spirit.
Pack this firmly in a percolator, and pass rectified spirit through it
till the spirit ceases to be coloured. Concentrate the spirituous solution
by distillation, so long as no deposit forms, and pour the residue, while
hot, into 12 times its volume of cold distilled water. Filter through
calico, and wash the residue on the filter with distilled water, till the
fluid ceases to precipitate with ammonia. To the united filtered liquid
add the ammonia in slight excess, let the precipitate completely subside,
pour off the supernatant fluid, collect the precipitate on a filter, and
wash it with distilled water till the fluid passes colourless. Diffuse the
moist precipitate through 12 oz. of distilled water, and add gradually,
with diligent stirring, sufficient hydrochloric acid to make the fluid
feebly but persistently acid.
Then add the animal charcoal, digest at a gentle heat for 20 minutes,
filter, and allow the liquid to cool. Add ammonia in slight, excess, and
when the precipitate has completely subsided, pour off the supernatant
liquid, collect the precipitate on a filter, and wash it with cold
distilled water till the washings cease to be affected by nitrate of
silver accidental with nitric acid. Lastly, dry the precipitate, first by
imbibition, with filtering paper, and then by the application of a gentle
heat.
_Prop._ Pure veratrine is perfectly white; but as usually met with, it is
a yellowish or greenish-white powder; it is highly acrid;
uncrystallisable; scarcely soluble in water, soluble in ether, and freely
soluble in hot alcohol; heated to about 125° Fahr., it fuses like wax, and
solidifies, upon cooling, to a transparent yellow mass. With the dilute
acid it forms salts, which are either amorphous or difficulty
crystallisable. The smallest possible portion of its powder causes violent
sneezing.
_Tests._ 1. Potassa, ammonia, and their carbonates, give flocculent white
precipitates which at first are not crystalline under the microscope, but
which, after some minutes, assume the appearance of small scattered
clusters of short prismatic crystals; they are insoluble in excess of
potassa and its carbonate, and only very slightly so in excess of
ammonia.——2. With sulphuric acid it strikes an intense red colour,
changing afterwards to crimson, and finally to violet.——3. A dilute acetic
solution of veratrine is turned to a superb red by strong sulphuric acid.
Veratrine is distinguished from brucine and the other alkaloids by its
fusibility——by the crystalline form of its precipitate with potassa,
and——by its reaction with oil of vitriol.
_Uses, &c._ “As an external application, it has been efficaciously
employed by Magendie in France, and by Dr Turnbull in this country; but
the extravagant eulogies of the latter have not tended to confirm the
reputation of this remedy.” (Dr A. T. Thomson.) From 6 to 12 gr.,
dissolved in 1 fl. oz. of rectified spirit, as a liniment; or 30 gr.,
mixed with 1 dr. of olive oil, and 1 oz. of lard, as an ointment, have
been occasionally found very serviceable in neuralgia, and other like
painful affections, and in gouty and rheumatic paralysis. As an internal
remedy it possesses no advantage, as it merely acts as a violent and
depressing cathartic.——_Dose_, 1/24 to 1/16 gr. In larger doses it acts as
a powerful irritant poison. For antidotes, &c., see ALKALOID.
=VERA′TRUM.= See WHITE HELLEBORE.
=VER′DIGRIS.= _Syn._ ÆRUGO, L.; VERT-DE-GRIS, Fr. This is a mixture of
several basic acetates of copper which have a green or blue colour. It is
obtained in the wine districts of the south of Europe, by the action of
refuse grapes, from which the juice has been expressed, on thin sheets of
copper. When pure it should dissolve, almost entirely, and without
effervescence, in dilute sulphuric acid. It is very poisonous; for
antidotes, see COPPER.
An inferior quality of verdigris is now prepared from pommage, or apple
marc, in the cider districts of England.
=Verdigris, Distilled.= _Syn._ CRYSTALLISED VERDIGRIS. This name is
applied to the normal acetate of copper, which is prepared in the wine
districts by dissolving ordinary verdigris, 1 part, in good distilled
vinegar, 2 parts; the operation being performed in a copper vessel by the
aid of a gentle heat and agitation; the solution is afterwards slowly
evaporated until a pedicle begins to form on the surface, when it is
transferred into glazed earthen pans (‘oulas’), in each of which are
placed 2 or 3 cleft sticks, and it is then left in a warm apartment for 14
or 15 days to crystallise.
A spurious article is often prepared by adding a solution of sulphate of
copper, 12-1/2 lbs. to a solution of sugar of lead, 19 lbs., or q. s.,
and filtering, evaporating, and crystallising the mixture.
There is an acetate of copper and lime which resembles distilled verdigris
in colour. It was manufactured pretty extensively in Scotland some years
ago, and fetched a high price, till Dr Ure published an analysis of it in
the ‘Edin. Phil. Trans.’ It is much inferior for all uses in the arts.
Pure distilled verdigris is entirely soluble in water, and is not
precipitated on the addition of sulphuric acid or of ammonia in excess.
=Verdigris, English.= _Prep._ Blue vitriol, 24 lbs.; white vitriol, 16
lbs.; sugar of lead, 12 lbs.; alum, 2 lbs. (all coarsely powdered); mix,
and heat them in a pot over the fire until they unite into a mass. Sold by
fraudulent dealers for foreign verdigris.
=VER′DITER.= _Syn._ BLUE VERDITER, REFINER’S VERDITER; CENDRES BLEUES, Fr.
A blue pigment, obtained by adding chalk, whiting, or milk of lime, to a
solution of copper in nitric acid; or, by triturating recently
precipitated and still moist carbonate of oxide of copper with hydrate of
lime.
_Prep._ A quantity of whiting or milk of lime is put into a tub, and upon
this the solution of copper is poured; the mixture is stirred every day
for some hours together, until the liquor loses its colour; it is then
poured off, and more solution of copper added; this is repeated until the
whiting or lime has acquired the proper colour; the whole is then washed
with water, drained, spread on chalk stones, and dried in the sun.
_Obs._ The cupreous solution employed in the above process is made by
neutralising the nitric solution obtained from the refiners of gold and
silver, by heating it along with metallic copper. For the finer qualities
of verditer the lime should be of the purest kind, and the cupreous
precipitate should be carefully triturated with it, after it is nearly
dry, by which a fine velvety appearance is produced. The ‘cendres bleues
en pâtes’ of the French differ from the above mainly in a solution of
chloride of copper being employed, and in the resulting green precipitate
being turned blue by the action of carbonate of potassa. Verditer is made
into crayons whilst moist, or dried into a powder, or it is used as a
water colour in the moist state.
=Verditer, Green.= _Syn._ BREMEN GREEN. The process for refiner’s verditer
frequently miscarries, and a green colour is produced instead of a blue
one. It may also be obtained directly by omitting the ‘blueing up’ with
carbonate of potassa, mentioned above.
=VER′JUICE.= _Syn._ AGRESTA, OMPHACIUM, L. The expressed juice of unripe
grapes. The term is also often extended to the expressed juice of the wild
or crab apple. It was formerly used as an astringent and refrigerant in
medicine; but it is now principally employed as an ingredient in sauces,
ragoûts, &c.
=VERMICEL′LI.= This, like macaroni, is prepared from a stiff paste made
of a peculiar fine kind of granular wheat flour, called semoule, which is
mixed up with hot water, and, after being well kneaded, is formed into
small ribands, cylinders, or tubes, by being placed in a vertical cylinder
press, the bottom of which is filled with proper-shaped holes, through
which it is driven by an iron plate or ‘follower’ being forced down by a
powerful screw. The pieces that protrude are broken off, twisted into any
desired shape upon paper, and dried. Those in the form of fillets or
ribands are called ‘lazagnes.’ Vermicelli contains a large amount of
gluten, and is extremely nutritious, although slightly less digestible
than the ordinary wheaten foods. See MACARONI.
=VER′MIFUGES.= _Syn._ ANTHELMINTICS; ANTHELMINTICA, HELMINTHAGOGA,
VERMIFUGA, L. Medicines employed to destroy or expel intestinal worms.
Some of these, as coarsely powdered tin and iron filings and cowhage, act
as mechanical agents, by irritating the worms; others have a specific
action upon worms, as male fern, kousso, santonin, &c.; others, again, owe
their power to their action as purgatives, as calomel, gamboge, jalap, &c.
See WORMS.
=VERMIL′ION.= _Syn._ FACTITIOUS CINNABAR, RED SULPHIDE OF MERCURY, RED
SULPHURET OF MERCURY. This article may be prepared both in the moist and
dry way; that of commerce is almost entirely obtained by the latter.
_Prep._ 1. By sublimation. Take of pure mercury, 202 parts; pure sulphur,
33 parts; fuse them together by a gentle heat, observing not to allow the
mass to take fire; when fused, cover over the vessel, and, when the whole
has become cold, powder the mass, and sublime it in a closed vessel, so
placed in a furnace that the flame may freely circulate and play upon it
to about half its height, the heat being at first gradually applied, and
afterwards augmented until the lower part of the subliming vessel becomes
red hot; the cold sublimate is broken into pieces, ground along with water
to a fine powder, elutriated, passed through a sieve, and dried. _Prod._
Fully 112% of the weight of the mercury employed.
2. In the humid way. (Brunner.) Take of pure quicksilver, 300 parts; pure
sublimed sulphur, 114 parts; triturate them together for several hours,
until a perfect ‘ethiops’ is formed, add gradually of caustic potassa, 75
parts, (dissolved in) water, 450 parts; continue the trituration for some
time longer, then gently heat the mixture in an iron vessel, at first
constantly stirring, but afterwards only from time to time, observing to
keep the beat at about 113°, or, at all events, under 122° Fahr., and to
add fresh water, to compensate for the portion evaporated. When the colour
begins to redden, great caution is requisite to preserve the mixture at
the lower temperature, and to keep the sulphuret of mercury perfectly
pulverulent; as soon as the colour becomes nearly ‘fine,’ the process must
be conducted with increased caution, and at a lower heat for some hours,
or until a rich colour is produced, when the newly-formed vermilion must
be elutriated with water, to separate any particles of metallic mercury,
and carefully dried. _Prod._ 332 parts of vermilion, equal in brilliancy
to the finest Chinese.
_Obs._ It has been said that the rich tone of Chinese vermilion may be
imitated by adding to the materials 1% of sulphuret of antimony, and by
digesting the ground sublimate, first in a solution or sulphuret of
potassium, and next in diluted hydrochloric acid, after which it must be
well edulcorated with water, and dried. Our own belief is, that the finer
qualities of vermilion owe their superiority of shade more to the care
bestowed on their sublimation, and the extent to which their division is
carried, than to anything else.
Vermilion is a beautiful and permanent red pigment, and works and covers
well both in oil and water.
=VERMIN.= This term has rather a large application, since, although it is
generally understood to be applied to rats, mice, and certain parasitic
insects infesting the dwellings and sometimes the bodies of men, it is
extended by the farmer, the gardener, and the breeder of game, to those
creatures from the depredations of which these three classes suffer
pecuniary loss. Hence it embraces not only foxes and polecats, but
weasels, stoats, hedgehogs, owls, hawks, kites, carrion crows, magpies,
wood-pigeons, hares, rabbits, rooks, moles, and small birds.
Whilst the attempted partial destruction of any of the classes of animals
or birds above specified may be regarded as of doubtful value, there can
be no question about the practice when it is carried to the verge of
extermination.
In this latter case the balance of nature is interfered with, and the
system of checks which she has established for the prevention of the undue
preponderance of one tribe of the animal kingdom over the other being
interfered with, the result will be the undue propagation of particular
species inimical to the operations of the husbandman, &c.
As illustrating this, we may mention the destruction to various crops in
France caused some years ago by the ravages of certain grubs and insects,
the unusual increase in the numbers of which was clearly traced to the
foolish practice, amongst French farmers, of shooting all the small birds.
See BUG, LOUSE, RATS.
=VERT′IGO.= Dizziness and swimming of the head. In its more serious forms
there is more or less mental confusion, the objects around the patient
appear in motion, the ears are oppressed with strange sounds, and visible
illusions are experienced, whether the eyes be closed or open, and in
darkness as well as in the light. The causes are fulness of the vessels of
the head, nervous derangement, general debility, hæmorrhage, the use of
narcotics, an overloaded stomach, and, in some cases, an empty one. It is
also frequently symptomatic of fevers and inflammations, and of a
condition threatening apoplexy. The treatment must be varied, according to
the cause and the peculiar habit or condition of the patient.
=VES′ICANTS.= _Syn._ EPISPASTICS; EPISPASTICA, VESICANTIA, L. Substances
which vesicate or raise blisters. Among these are the cantharis or
blistering fly, mezereon, croton oil, boiling water, &c.; the first only
of which is now in common use in England.
“It is a principle sufficiently established with regard to the living
system, that, where a morbid action exists, it may often be removed by
inducing an action of a different kind, in the same or a neighbouring
part. On this principle is explained the utility of blisters in local
inflammation and spasmodic action, and it regulates their application in
pneumonia, gastritis, hepatitis, phrenitis, angina, rheumatism, colic, and
spasmodic affections of the stomach——diseases in which they are employed
with the most marked advantage. A similar principle exists with respect to
pain; exciting one pain often relieves another. Hence blisters often give
relief in toothache, and some other painful affections. Lastly, blisters,
by their operation, communicate a stimulus to the whole system, and raise
the vigour of the circulation. Hence, in part, their utility in fevers of
the typhoid kind, though in such cases they are used with still more
advantage to obviate or remove local inflammation.” (‘Med. Lex.’)
Blisters are commonly prepared with cantharides plaster, or with some
other preparation of cantharides; and, in the former case, are usually
lightly covered with the powdered fly. In order to prevent the action of
the cantharides upon the mucous membrane of the bladder, blistering
plasters are often sprinkled with a little powdered camphor, or, better
still, are moistened with camphorated ether, which leaves a thin layer of
camphor. In all these cases the layer should not be too thick, for in that
case the plaster would not take effect.
When it is not wished to maintain a discharge from the blistered part, it
is sufficient to make a puncture in the vesicle, to let out the fluid; but
when the case requires the blister to be ‘kept open,’ as it is called, the
whole of the detached cuticle is carefully removed with a pair of
scissors, and the part is dressed with either the ointment of cantharides
or of savine, at first more or less diluted with lard, or simple ointment,
with an occasional dressing of resin cerate. According to Mr Crowther, the
blistered surface is best kept clean by daily fomentation with warm water.
Of late years, to obviate the unpleasant effects occasionally arising
from the common blister, various compounds having cantharides for their
base have been brought before the public. Of these, the vesicating
collodion noticed under COLLODION is the most convenient and effective.
The following also deserve notice:——
1. Take of cantharides, in fine powder, 2 parts; spermaceti, 2 parts;
olive oil, 4 parts; white wax, 8 parts; water, 10 parts; simmer, with
constant agitation, for 2 hours, strain through flannel, separate the
plaster from the water, gently remelt it with common turpentine, 1 part,
and spread the mass whilst still fluid. This nearly resembles the form
recommended by MM. Henry and Guibourt.
2. (P. Cod.) Distil off the ether from a concentrated ethereal tincture of
cantharides, melt the oily residue with twice its weight of white wax, and
spread the mixture on thin oiled silk, or on cloth, prepared with wax
plaster.
3. (Oettinger.) Cantharidal ether (prepared from cantharides, l part;
ether 2 parts), and sulphuric ether, of each 10 dr.; turpentine and black
resin, of each 2-1/2 dr.; mix, dissolve, and apply it to the surface of
stretched silk or taffeta which has been previously prepared with two
coatings of a solution of isinglass.
4. (CHARTA EPISPASTICA, B. P.). Digest 4 oz. of white wax, 1-1/2 oz.
spermaceti, 2 oz. fluid of olive oil, 3 oz. of resin, 1 oz. of cantharides
in powder, and distilled water 6 oz., in a water bath for two hours,
stirring constantly, strain, and separate the plaster from the watery
liquid. Mix 1/4 oz. fl. of Canada balsam with the plaster, melted in a
shallow vessel, and pass strips of paper over the hot liquid, so that one
surface of the paper shall receive a thin coating of plaster. It may be
convenient to employ paper, ruled in square inches.
5. (CHARTA SINAPIS, B. P.) Black mustard seeds, in powder, 1 oz.; solution
of gutta percha, 2 oz., or q. s. Mix so as to make a semi-fluid, and
having poured this into a shallow flat-bottom vessel, such as a dinner
plate, pass strips of cartridge paper ever its surface, so that one side
of the paper shall receive a thin coating of the mixture. Then lay the
paper on a table, with the coated side upwards, and let it remain exposed
to the air until the coating has hardened. Before being applied let the
mustard paper be immersed for a few seconds in tepid water.
6. (VESICATING SPARADRAP, P. Cod.) Gum elini, 1 oz.; olive oil, 1/2 oz.;
basilicon ointment, 2-1/4 oz.; resin, 1 oz.; yellow wax, 3-3/4 oz.;
cantharides, in fine powder, 4-1/4 oz. Melt the first five substances
together, and stir in the cantharides; when sufficiently cold, and well
mixed, spread on waxed strips of linen.
_Obs._ The above compounds are spread on leather, linen, paper, silk,
oiled silk, taffeta, &c., and then form the numerous compounds vended
under the names of——blistering tissue, rannus vesicatorius, papier
epispastique, sparadrapum vesicatorium, taffetas vesicans, tela
vesicatoria, &c.
Acetic extract of cantharides, croton oil, or extract of mezereon, is
sometimes substituted for the ethereal extract ordered in the above
formulæ.
The ‘papier epispastique’ of Vée is prepared of three strengths, which are
respectively distinguished by the colours white, green, and red. The
composition is made by boiling powdered cantharides for an hour with
water, lard, and green ointment, or with lard coloured with alkanet root,
adding white wax to the strained fats, and spreading the mixture whilst
fluid:——No. 1 is made with 10 oz. of cantharides to 4 lbs. of lard; No. 2
of 1 lb. of cantharides to 8 lbs. of green ointment; and No. 3, of 1-1/2
lb. of flies to 8 lbs. of reddened lard. To each are added 2 lbs. of white
wax. (Dorvault.)
The magistral blister of Valleix is a revival of the vesicating epithem.
See BLISTER, CANTHARIDES, COLLODION, &c., and _below_.
=VESICA′TION.= The formation of a blister is a vital process, and its
success may be taken as a proof of the presence of life. Hence a French
physician, Dr Mandl, has suggested such a stimulation of the skin as would
ordinarily cause a blister as a test of life, in those cases of
long-continued trance which we occasionally hear of, where all the
functions of life seem to be extinct. Dr Mandl’s plan is to apply a stick
of lunar caustic. The application of a little strong vinegar of
cantharides, or other cantharidal blister, of the size of a sixpenny
piece, or of two or three spoonfuls of boiling water by means of a bent
tube of like diameter, is however, more certain and satisfactory.
=VESICA′TORIN.= _Syn._ CANTHARIDIN, CANTHARIDINA, CANTHARIDES CAMPHOR. The
blistering principle of Spanish flies, discovered by M. Robiquet.
_Prep._ 1. (P. Cod.) Exhaust powdered cantharides with concentrated
alcohol by percolation; distil off the spirit from the filtered tincture,
and leave the residuum to deposit crystals; these may be purified by
dissolving them in boiling alcohol, digestion with animal charcoal,
filtration whilst hot, and crystallising by refrigeration.
2. (Thierry.) Macerate cantharides (in coarse powder) for several days in
ether, in a closed displacement apparatus; then, after the whole of the
soluble matter has been extracted by the addition of fresh portions of
ether, pour on sufficient water to displace the retained ether; next
distil off the ether, dissolve the remaining extract in boiling alcohol,
filter while hot, and abandon the filtrate to spontaneous evaporation.
_Prod._ ·5%.
3. Digest the aqueous extract of cantharides in hot alcohol, filter,
evaporate to dryness, digest the residuum in sulphuric ether, evaporate,
and slightly wash the resulting crystals with cold alcohol.
_Prop., &c._ Micaceous plates resembling spermaceti; fusible; vaporisable;
insoluble in water; soluble in ether, oils, acetic acid, and hot alcohol;
powerfully vesicant and poisonous. Its vapour, even at ordinary
temperatures, frequently produces temporary blindness. The 1-100th part of
a grain, placed on a piece of paper, and applied to the edge of the lower
lip, caused small blisters in 15 minutes, which, when rubbed with a little
simple cerate, extended over a large surface, and covered both lips with
blisters. (Robiquet.)
=VETCH.= The common name of various leguminous plants of the genera
_Vicia_ and _Ervum_, now much cultivated as green fodder for milch cows
and working stock. The seeds (tares) were formerly reputed detersive and
astringent. Those of “the Canadian variety make good bread.” (Lindley.)
=VET′ERINARY MEDICINES.= The common form of medicine for horses is that
popularly known as horse balls. They are usually prepared by mixing the
dry ingredients, in the state of powder, with a sufficient quantity of
treacle, or syrup bottoms, to give the mass a proper consistence for
rolling into balls; adding, when necessary, linseed meal, or any other
simple powder, to increase the bulk. The usual practice among the
veterinary druggists is to keep a compound known in the trade as
‘ball-mass,’ or ‘common mass,’ ready prepared to give form and bulk to
more active ingredients. This is usually made of about equal parts of
linseed meal and treacle, together with a little palm or lard, thoroughly
incorporated by kneading with the hands; and it is kept in a cool
situation, tied over to prevent it drying and hardening. For use, the
ball-masses are either rolled or moulded into small cylinders of about
1-1/2 to 1-3/4 oz. in weight; and in size, from 2 to 2-3/4 inches long,
and from about 1/2 to 7/8 of an inch in diameter; and they are wrapped in
soft paper, which is administered with them. Those for dogs are commonly
formed into large boluses or nut-like pieces. The common practice in some
houses of adding a little salt of tartar or acetate of potassa to
ball-masses kept in stock, for the purpose of preserving them in a soft
state, is not to be commended, since these articles decompose many of the
saline and mineral compounds which are subsequently added to them.
Medicines for neat cattle are always administered in a liquid form,
popularly called drenches. A similar plan is adopted with small cattle, as
sheep and goats. For these, however, the quantity should seldom exceed 1/4
pint. In all cases, drenches should be very slowly administered.
The following are a few useful horse-balls:
=Alterative Balls.=——1. Levigated sulphide of antimony, sulphur, and
linseed meal, of each 3 oz.; nitre, 4 oz.; palm oil, q. s. to form a
mass; for 12 balls. One to be taken every day, or every other day.
2. (Bell.) Sulphide of antimony, nitre, sulphur, and Æthiops mineral, of
each 3 oz.; soft soap, 10 oz.; oil of juniper, 1/2 oz.; for 12 balls. As
the last.
3. (White.) Sulphide of antimony, caraways, and treacle, of each 1/4 oz.;
for one ball. As the last.
CORDIAL BALLS.——1. (Blaine). Coriander seed, caraway, and gentian, of each
8 oz.; ginger, 4 oz.; oil of aniseed, 1/2 oz.; honey or palm oil, q. s. to
form a mass. Cordial, warming, and stomachic.——_Dose_, 1-1/2 oz.
2. (Hill.) Anise, caraway, and cumin seed, of each 4 lbs.; ginger, 2 lbs.;
treacle, q. s.; divide into 1-3/4 oz. balls. _Prod._ 21 lbs.
COUGH BALLS.——1. (Blaine.) Ipecacuanha, 1 dr.; camphor 2 dr.; honey, q. s.
to form a ball. One night and morning.
2. (B. Clark.) Emetic tartar and benzoin, of each 2 dr.; squills, 4 dr.;
spermaceti and balsam of copaiba, of each 1 oz.; elecampane and sulphur,
of each 2 oz.; syrup of poppies, q. s. to mix; for 8 balls. As the last.
DIURETIC BALLS.——1. (Bracy Clark.) Nitre and common turpentine, of each 1
lb.; Castile soap, 1/2 lb.; barley meal, 2-1/2 lbs., or q. s. For
common-sized balls.
2. (Morton.) Digitalis 1 oz.; aloes, 2 oz.; liquorice, 13 oz.; honey or
Barbadoes tar, q. s. to mix; for 1-oz. balls. One, twice a day with care.
PHYSIC BALLS, PURGING B., CATHARTIC B.——1. Aloes and hard soap, of each 5
oz.; salt of tartar and cayenne pepper, of each 1 oz.; melt together. For
8 balls.
2. (Vet. Coll.)——_a._ (Common physic ball.) Aloes, 8 oz.; treacle, 3 oz.;
olive oil, 1 oz.; melted together.——_Dose_, 1 to 1-1/2 oz.
_b._ (Stronger ball.) To each dose of the last, add of croton oil, 4 to 8
drops.
=Obs.= The _dose_ of the above is 1 ball, fasting in the morning, preceded
by a bran mash, on one or two successive nights, and followed by gentle
exercise until the ball begins to operate.
WORM BALLS.——1. Barbadoes aloes, 5 dr.; calomel and ginger, of each 2 dr.;
oil of cloves, 12 drops; treacle, q. s. for a ball.
2. (J. Bell & Co.) Barbadoes aloes, 5 to 8 dr.; powdered tin,Æthiops
mineral, and ginger, of each 2 dr.; oils of aniseed and savine, of each 20
drops; treacle, q. s. for a ball.
3. (Clater.) Sulphur and emetic tartar, of each 1 dr.; linseed meal, 4
dr.; palm oil, q. s. to form a ball. One every morning, having prepared
the animal with a physic ball containing 1 dr. of calomel. See BALLS; also
Tuson’s ‘Veterinary Pharmacopœia.’
=VIN′EGAR.= _Syn._ ACETUM, L.; VINAIGRE, Fr. Dilute acetic acid, more or
less contaminated with gum, sugar and vegetable matter.
1. MALT VINEGAR; ACETUM, BRITISH VINEGAr (B. P.); ACETUM BRITTANNICUM
(Ph. L. & E.), L. This is the ordinary coloured vinegar consumed in this
country, and is correctly described in the Ph. L. as “impure (dilute)
acetic acid, prepared by fermentation from an infusion of malt
(malt-wort).”
In the manufacture of MALT VINEGAR a mixture of malt and barley is mashed
with hot water, and the resulting wort fermented, as in the common process
of brewing. The liquor is then run into barrels, placed endways, tied over
with coarse canvas, and arranged side by side in darkened chambers,
moderately heated by a stove, and freely supplied with air. Here it
remains till the acetous fermentation is nearly complete, which usually
occupies several weeks, or even months. The newly formed vinegar is next
run off into two large tuns, furnished with false bottoms, on which some
‘rape’ (the pressed cake from making domestic wines, or the green twigs or
cuttings of vines) is placed. One of these vessels is wholly, and the
other only about 3-4ths, filled. The fermentation recommences, and the
acetification proceeds more rapidly in the latter than in the former tun,
and the liquor it contains consequently matures the sooner. When fit for
sale, a portion of the vinegar is withdrawn from the smaller quantity, and
its place supplied with a like quantity from the full tun, and this in its
turn is refilled from the barrels before noticed. This process is carried
on with a number of tuns at once, which are all worked in pairs.
_Prop., &c._, The general properties of malt vinegar are well known. Its
pleasant and refreshing odour is chiefly derived from acetic acid and
acetic ether. Its strength is distinguished by the makers as Nos. 18, 20,
22, and 24; the last of which, also called ‘proof vinegar,’ is the
strongest, and usually contains about 4·6% of real or about 5% of glacial
acetic acid. Its density varies according to the quantity of foreign
matter which it contains. Sp. gr. 1·017 to 1·019——B. P. This vinegar
usually contains a small quantity of sulphuric acid. The presence of
1-1000th part of this acid is allowed by law.
_Pur._ “Brownish; of a peculiar odour. Its sp. gr. is 1·019. 1 fl. oz. of
the acid is saturated by 1 dr. of the crystals of carbonate of soda. If,
after 10 minims of solution of chloride of barium have been added to the
same quantity, more of the chloride be poured into the filtered acid,
nothing further is thrown down. The colour is not changed by the addition
of hydrosulphuric acid.” (Ph. L.)
2. WINE VINEGAR, FRENCH V.; ACETUM GALLICUM (Ph. E. & D.), A. VINI, L.;
VINAIGRE D’ORLEANS, Fr. This is prepared, in wine countries, from grape
juice and inferior new wines, worked up with wine-lees, by a nearly
similar process to that adopted for malt vinegar. That prepared from white
wine (WHITE-WINE VINEGAR) is the most esteemed. It is purer and pleasanter
than malt vinegar. Sp. gr. 1·014 to 1·022——Ph. E.; 1·016——Phillips. It
usually contains from 5 to 6% of acetic acid. “100 parts of good Orleans
vinegar should require 10 parts of dry carbonate of potassa for
saturation.” (Soubeiran.)
3. GERMAN, OR QUICK-METHOD OF MAKING VINEGAR; PROCESS OF HAM. This method
is based upon the fact, that acetification is the mere oxidation of
alcohol in contact with organic matter. Hence, by employing dilute
alcohol, or liquors containing it, and by vastly enlarging the surface of
the liquid exposed to the air at a proper temperature, we may reduce the
period occupied in acetification from weeks to as many hours. In practice
this is effected by causing the dilute spirit, previously mixed with
1-1000th part of sugar or malt extract, or the fermented and clarified
malt-wort, to slowly trickle down through a mass of beech shavings steeped
in vinegar, and contained in a vessel called a vinegar generator
(essigbilder), or graduation vessel. This is an oaken tub, narrower at the
bottom than at the top, furnished with a loose lid or cover, below which
is a perforated shelf (colander or false bottom), having a number of small
holes, which are loosely filled with packthread about 6 inches long, and
prevented from falling through by a knot at the upper end. The shelf is
also perforated with four open glass tubes, as air-vents, each having its
ends projecting above and below the shelf. This arrangement is repeated a
second and a third time, or even oftener, according to the size of the
vessel. The tube or graduator at its lower part is pierced with a
horizontal row of eight equidistant round holes, to admit atmospheric air.
One inch above the bottom is a syphon-formed discharge pipe, whose upper
curvature stands one inch below the level of the air-holes in the side of
the tub. The floors or partitions of the tub or generator being covered
with birch twigs or beech chips to the depth of a few inches, the
alcoholic liquor (first heated to between 75° and 83° Fahr.,) is
introduced at the upper part of the apparatus. This immediately commences
trickling slowly down through the holes by means of the packthreads,
diffuses itself over the chips or twigs forming the respective strata,
slowly collects at the bottom of the tub, and then runs off by the
syphon-pipe. The air enters by the circumferential holes, circulates
freely through the tub, and escapes by the glass tubes. As the
acetification proceeds, the temperature of the liquid rises to 100° or
105° Fahr., and remains stationary at that point while the action goes on
favorably. The alcoholic solution or wort requires to be passed three or
four times through the cask before acetification is complete, which is, in
general, effected in from 24 to 36 hours.
_Obs._ For the production of a superior vinegar by this process, it is
necessary that the spirit employed be sufficiently pure not to contaminate
the product with its flavour or odour, and that the malt-wort should be
fermented and treated with all the care usually employed in the production
of beer. The best English manufacturers who have adopted this process are
in the habit of filtering or clarifying their fermented wash, and also of
storing it away for several months before they subject it to acetification
in the graduator. The most favorable temperature for the process is about
90° Fahr., and this should be preserved, as much as possible, by
artificial means. _Prod._ A malt-wort of the sp. gr. 1·072, or, in
“technical language, weighing about 26 lbs. per barrel, afforded a vinegar
containing 5·4% of pure acetic acid, and a residuary extract of 10 lbs.,
for 36 galls. The former of these would indicate 35 lbs. of sugar, or 13·7
lbs. per barrel of gravity; whilst the latter shows 3·8 lbs. per barrel;
the two united being only 17·5 lbs., instead of 26, the original weight.
The loss, therefore, has been 8·5 lbs., or from a sp. gr. of 1·072 to less
than 1·050.” (Ure.) Thus, about one third of all the extractive matter of
the malt is lost or dissipated during the processes of fermentation and
acetification. According to Knapp, a mixture of about 80 galls, of water,
9 galls. of spirit of from 44 to 45% Tralles (18 or 20 u. p.), and 3
galls. of vinegar containing 3·5% of real acid, forming together 92
galls., yield, on an average, an almost equal quantity of vinegar, or
about from 90 to 91 galls. of the above stated strength.
4. WOOD VINEGAR. See PYROLIGNEOUS ACID.
5. OTHER VARIETIES OF VINEGAR, of minor importance; chiefly domestic, and
commonly ‘worked’ as malt vinegar,——ALE VINEGAR, ALEGAR; ACETUM CEREVISIÆ.
From strong pale ale which has soured.——ARGOL VINEGAR; ACETUM EX TARTARO.
From white argol or cream of tartar, 1 lb.; dissolved in boiling water, 2
galls.; with the addition, when cold, of proof spirit of whiskey, 3
pints.——CRYSTAL VINEGAR. Pickling vinegar, discoloured with fresh burnt
animal charcoal.——CIDER VINEGAR. From cider, worked as malt
vinegar.——GERMAN HOUSEHOLD VINEGAR. From soft water, 7-1/2 galls.; honey
or brown sugar, 2 lbs.; cream of tartar, 2 oz.; corn spirit or whiskey, 1
gall.——GOOSEBERRY VINEGAR. From bruised gooseberries and brown sugar, of
each 1-1/4 lb.; water, 1 gall. Other fruits may be substituted for
gooseberries.——PICKLING VINEGAR. The strongest pale malt vinegar——RAISIN
VINEGAR. From the marc left from making raisin wine, 1 cwt. to every 12 or
15 galls. of water, along with a little yeast.——SUGAR VINEGAR. From brown
sugar, 4 lbs. to each gallon of water.——WHISKEY VINEGAR. From whiskey, 1
pint; sugar, 2 oz.; yeast, a dessert-spoonful.
_Pur., Tests, and Assay._ These are, for the most part, rather fully
noticed under ACETIC ACID, ACETIMETRY, and above. The following additional
tests, &c., may, however, be useful:——1. Paper written on or smeared with
pure vinegar is not charred when strongly warmed before the fire; if it
is, the sample examined contained fully 2% of oil of vitriol.——2. A small
porcelain capsule, or china cup, dipped into a solution of sugar in 30
times its weight of water, and then heated to a temperature equal to that
of boiling water, is not materially discoloured when a drop of pure
vinegar is poured on it; but a spot of an intensely brown or black colour
is formed if the sample contains only 1-300th part of sulphuric acid; if
it contains only 1-1000th part, the spot is olive green; and if a less
quantity, then only of a pale green colour.——3. The heavy white
precipitate given with chloride of barium (see _above_) shows the presence
of sulphuric acid; each grain, after being dried, and gently ignited,
represents ·344 gr. of dry sulphuric acid. If the precipitate from 1000
gr. of the vinegar exceeds 2-1/2 gr., it contains an illegal quantity of
this acid.——4. If a solution of nitrate of silver gives a cloudy white
precipitate, hydrochloric acid is present.——5. If, after the addition of 2
or 3 gr. of carbonate of potash, and evaporation of the sample to dryness,
the residuum deflagrates when ignited, the sample under examination
contains nitric acid.——6. If the vinegar be blackened by sulphuretted
hydrogen or hydrosulphuret of ammonia, it contains either lead or copper.
If it gives a yellow precipitate with iodide of potassium or chromate of
potash, the metal is lead. If ferrocyanide of potassium gives a
bronze-brown coloured precipitate, or a little olive oil, when agitated
with some of the vinegar, be turned green, the metal is copper.——7. If a
small sample, gently evaporated to dryness, leaves more than 1% of
residuum, and this has a sweet taste, it is undecomposed sugar. The
presence of acrid substances, as capsicum, chillies, grains of paradise,
mustard seed, pellitory of Spain, pepper, &c., may be detected by
neutralising the acidity of the vinegar with carbonate of soda, when the
acrid taste of the adulterant will be readily perceived.
=Vinegar, Anti′hysteric.= _Syn._ ACETUM ANTI′HYSTERICUM. _Prep._ Castor, 2
dr.; galbarium, 4 dr.; rue, 1 oz.; vinegar, 3 lbs.; macerate and strain.
=Vinegar, Aromat′ic.= _Syn._ ACETUM AROMATICUM, L. _Prep._ 1. Glacial
acetic acid, 1 lb.; oil of cloves, 1-1/2 dr.; oil of rosemary, 1 dr.; oils
of bergamot, cinnamon, pimento, and lavender, of each 1/2 dr.; neroli, 20
drops; camphor, 2-1/2 oz.; rectified spirit, 2 fl. oz.; mix. Very fine.
2. (Henry’s.) From glacial acetic acid, strongly scented with the oils of
cloves, lavender, rosemary, and _Calamus aromaticus_ to which the usual
quantity of camphor is added. This is the formula adopted at Apothecaries’
Hall.
3. (Extemporaneous.) From acetate of potash (dry), 1 dr.; oil of vitriol,
20 drops; oils of lemon and cloves, of each 3 drops.
_Obs._ Aromatic vinegar is used as a pungent and refreshing perfume, in
faintness, &c. For this purpose it is generally dropped on a small piece
of sponge placed in a stoppered bottle or a vinaigrette. It is highly
corrosive, and should therefore be kept from contact with the skin and
clothes.
=Vinegar, Camp.= _Prep._ Take of sliced garlic, 8 oz.; Cayenne pepper,
soy, and walnut ketchup, of each 4 oz.; 36 chopped anchovies; vinegar, 1
gall.; powdered cochineal, 1/2 oz.; macerate for a month, strain, and
bottle.
=Vinegar, Cam′phorated.=
=Vinegar of Canthar′ides.= _Syn._ BLISTERING VINEGAR; ACETUM CANTHARIDIS
(B. P., Ph., L. E. & D.), L. _Prep._ 1. (Ph. L.) Cantharides, in powder, 2
oz.; acetic acid, 1 pint; macerate, with agitation, for 8 days, then
press, and strain.
2. (Ph. E.) Cantharides, 3 oz.; euphorbium, 1/2 oz.; acetic acid, 5 fl.
oz.; pyroligneous acid, 15 fl. oz.; macerate a week.
3. (Ph. D.) Spanish flies, 4 oz.; strong acetic acid, 4 fl. oz.;
commercial acetic acid (sp. gr. 1·044), 16 fl. oz.; macerate, as before,
for 14 days.
4. (B. P.) Cantharides, in powder, 2; glacial acetic acid, 2; acetic acid
(28 per cent.), 18, or a sufficiency: add the glacial acetic acid to 13 of
acetic acid, and in this mixture digest the cantharides for two hours at a
temperature of 200° F.; when cold, place them in a percolator, and when
the liquid ceases to drop, pour over the residuum the remaining 5 of
acetic acid, and when the percolation is finished, press and make the
whole liquid up to 20.
_Uses, &c._ As a counter-irritant, and to raise blisters. For the last
purpose it is applied on a piece of lint, evaporation being prevented with
a piece of oiled skin or thin sheet gutta percha. The last is the best,
and, indeed, the only effective form; the others being too weak. “If the
acetic acid be strong, a blister will be as rapidly raised without the
cantharides as with them.” (Dr A. T. Thomson.)
=Vinegar of Capsi′cum.= _Syn._ ACETUM CAPSICE. _Prep._ Capsicum, 1 oz.;
vinegar, 24 oz. Used as gargle.
=Vinegar of Col′chicum.= _Syn._ ACETUM COLCHICI (Ph. L. E. & D.), L.
_Prep._ 1. (Ph. L.) Dried corms of colchicum or meadow saffron, 3-1/2 dr.;
dilute acetic acid, 1 pint; macerate for 3 days, then press out the
liquor, and, after defecation, add to the strained liquid proof spirit,
1-1/2 fl. oz.
=Vinegar, Cur′rie.= _Prep._ From currie powder, 1/2 lb.; vinegar, 1 gall.;
infuse for a week. Used as a flavouring. Other like vinegars may be made
in the same way.
=Vinegar of Gar′lic.= _Syn._ ACETUM ALLII. _Prep._ Fresh garlic, 1 oz.;
distilled vinegar, 12 oz.
2. (Ph. E.) Fresh colchicum bulbs (dried), 1 oz.; distilled vinegar, 16
fl. oz.; proof spirit, 1 fl. oz.
3. (Ph. D.) Dried colchicum bulbs, 1 oz.; acetic acid (1·044), 4 fl. oz.;
distilled water, 12 fl. oz.; as before, but prolonging the maceration for
7 days.
_Obs._ Vinegar of colchicum is chiefly used in gout. _Dose_, 20 drops to 1
fl. dr. The Dublin preparation is about three times as strong as the
others, and the dose must therefore be proportionately less.
=Vinegar, Distil′led.= _Syn._ ACETUM DESTILLATUM (Ph. L. & E., and Ph. D.
1826), L. _Prep._ 1. (Ph. L.) Vinegar, 1 gall.; distil in a sand bath, 7
pints. Sp. gr. 1·0065.
2. (Ph. E.) Vinegar (preferably French), 8 parts; distil over with a
gentle heat, 7 parts; and dilute the product, if necessary, with distilled
water, until the sp. gr. is 1·005.
_Pur., &c._ “1 fluid oz. is saturated by 57 gr. of crystallised carbonate
of soda.” (Ph. L.) 100 gr. are saturated by 13 gr. of crystallised
carbonate of soda. It contains about 4·6% of real acetic acid. If a pewter
worm is used, a portion of lead is dissolved, and the product becomes
cloudy and poisonous. Distilled vinegar is more agreeable than pure dilute
acetic acid of the same strength.
=Vinegar of Fox′glove.= _Syn._ ACETUM DIGITALIS. (Ph. G.) _Prep._ Dried
foxglove, 1 oz.; vinegar, 9 oz. (by weight); rectified spirit, 1 oz. (by
weight). Macerate for 8 days, press and filter.——_Dose_, 30 minims.
=Vinegar of Lav′ender.= _Syn._ ACETUM LAVANDULÆ. (P. Cod.) _Prep._ Digest
1 troy oz. of dried lavender flowers with 12 oz. of vinegar for 10 days.
The vinegars of other flowers are made in the same manner.
=Vinegar of Lobelia.= _Syn._ ACETUM LOBELIÆ. _Prep._ Lobelia in moderately
coarse powder, 4 troy oz. Diluted acetic acid, 2 pints (o. m.). Macerate
for 7 days.
=Vinegar, Marseilles.= _Syn._ VINEGAR OF THE FOUR THIEVES, PROPHYLACTIC
VINEGAR; ACETUM PROPHYLACTICUM, A. ANTISEPTICUM, A. THERIACALE, A. QUATUOR
FURUM, L.; VINAIGRE DES QUATRE VOLEURS, Fr. _Prep._ Take of the summits of
rosemary and flowers of sage (dried), of each 4 oz.; dried lavender
flowers, 2 oz.; cloves, 1 dr.; distilled vinegar, 1 gall.; digest for 7
days, press, and filter. Used as a corrector of bad smells, and formerly
as a prophylactic against the plague, and other contagious diseases. It is
said to have been a favourite preventive with Cardinal Wolsey, who always
carried some with him. The original formula also contained, of garlic, 1/4
oz.; fresh rue, 1-1/2 oz.; and camphor, dissolved in spirit, 1 oz.
=Vinegar of Mus′tard.= _Syn._ ACETUM SINAPIS (Beral). _Prep._ Mustard, 1
oz.; vinegar, 12 oz.; distil 8 oz. For outward use, as a counter-irritant.
=Vinegar of O′′pium.= _Syn._ ACETUM OPII (Ph. E. & D.), L. _Prep._ 1. (Ph.
E.) Opium, sliced, 4 oz.; distilled vinegar, 16 fl. oz.; macerate for 7
days, press, and filter.——_Dose_, 5 to 20 drops.
2. (Ph. D.) Opium, in coarse powder, 1-1/2 oz.; dilute acetic acid, 1
pint; macerate for 7 days.——_Dose_, 10 or 12 to 60 drops.
_Obs._ These were intended to supersede the old ‘black drop,’ which they
closely resemble in their action.
=Vinegar, Rasp′berry.= _Syn._ ACETUM RUBI IDÆI, L.; VINAIGRE FRAMBOISE,
Fr. _Prep._ 1. Bruised ripe raspberries and white wine vinegar, of each 3
pints; macerate for 3 days, press, strain, and to each pint add of white
sugar, 1 lb.; boil, skim, cool, and at once bottle. Some persons add 2 fl.
oz. of brandy to each pint.
2. (P. Cod.) Fresh raspberries, picked from their calices, 3 lbs.; (1
lb.——Ph. Bor.); good vinegar, 2 lbs.; macerate, in glass, for a fortnight,
then strain, without pressure.
_Obs._ In a similar manner may be made cherry vinegar, strawberry vinegar,
and the vinegars of all other like fruits.
=Vinegar of Rue.= _Syn._ ACETUM RUTÆ. (Ed. Ph. 1744). _Prep._ Rue, 1 lb.
troy; vinegar, 1 gall.
=Vinegar of Squills.= _Syn._ ACETUM SCILLÆ (Ph. L. E. & D.), ACEUM
SCILLITICUM, L. _Prep._ 1. (Ph. L.) Take of squills, recently dried and
bruised, 2-1/2 oz.; dilute acetic acid, 1 pint; macerate with a gentle
heat in a covered vessel for 3 days, then press out the liquor, and, after
defecation, add to the strained liquid, proof spirit, 1-1/2 fl. oz. The
Edinburgh and Dublin Colleges direct cold maceration for 7 days in a glass
vessel, and the Dublin omits the spirit.
2. (Wholesale.) From squills, 7 lbs.; distilled vinegar, 6 galls.;
macerate in the cold for 10 days, press, and filter. Expectorant and
diuretic.——_Dose_, 1/2 to 1-1/2 fl. dr.; in chronic pulmonary affections,
dropsies, &c.
=Vinegars (Cul′inary).= _Prep._ 1. BLACK PEPPER VINEGAR, CAPER V.,
CAPSICUM V., CELERY-SEED V., CHILLIE V., CRESS-SEED V., GARLIC V., GINGER
V., HORSERADISH V., ONION V., RED-ROSE V., SEVILLE-ORANGE-PEEL V., SHALLOT
V., TRUFFLE V., WHITE PEPPER V., with several others of a like kind, are
made by steeping about an oz. of the respective articles in a pint of good
vinegar for 14 days, and straining.
2. BASIL V., BURNET V., CELERY V., CHERVILLE V., ELDER-FLOWER V.,
GREEN-MINT V., TARRAGON V., with several others from like substances, are
prepared from 2 to 3 oz. of the leaves to each pint of vinegar; the whole
being frequently shaken for 14 days, then strained and bottled. They are
used in cookery. The culinary vinegars may also be prepared in the same
manner as the ‘culinary spirits’ and ‘tinctures,’ by simply substituting
strong pickling vinegar for the spirit.
=Vinegars (Perfumed).= _Syn._ ACETA ODORIFERA, L. _Prep._ From the dried
flowers, 1 to 2 oz., or the fresh flowers, 2 to 4 oz.; strongest
distilled vinegar, 1 pint; digest for a week, strain with pressure, and
repeat the process with fresh flowers if necessary. They may also be made
by adding 15 to 20 drops, or q. s., of the respective essential oils to
the vinegar. In a similar way are prepared the vinegars of clove-gilly
flowers, elder flowers, lavender f. (vinaigre distillé de lavande), musk
roses, orange flowers (fresh), Provins roses, red roses (vinaigre de rose;
acetum rosatum), rosemary flowers (vinaigre de rosmarin; acetum
anthosatum), tarragon flowers, &c. &c. Another excellent plan is to add 1
fl. oz. of glacial acetic acid to each pint of the respective perfumed
spirits. This answers admirably for acetic eau de Cologne and like
perfumes.
=VI′NOUS FERMENTATION.= _Syn._ ALCOHOLIC FERMENTATION. The peculiar change
by which sugar, in solution, is converted into carbonic acid, which is
eliminated, and into alcohol, which remains in solution in the fermented
liquor.
The presence of a ‘ferment’ is essential to excite the vinous
fermentation, as a solution of absolutely pure sugar remains unaltered,
even though exposed to the conditions most favourable to its accession. In
the juices of the sweet fruits, and in those vegetable solutions that
spontaneously run into a state of fermentation, the ferment is supplied by
nature, and is intimately associated with the saccharine matter. In the
juice of those grapes which produce the more perfect wines, the relative
proportions of the exciters of fermentation and the sugar are so
accurately apportioned, that the whole of the former are decomposed, and
nearly the whole of the latter is converted into alcohol; so that the
liquid (wine) is left in a state but little liable to future change. An
infusion of malt, however, in which the nitrogenised matters (gluten,
vegetable albumen, &c.) are absent, or at least present in too small
quantities to vigorously excite the vinous fermentation, undergoes a mixed
species of decomposition, with the formation of products widely different
from those that result from the true vinous fermentation; or, in other
words, the liquid becomes spoiled. But if a ferment (yeast) be added to
this infusion of malt under the above circumstances, and in the proper
proportion to the sugar present, the true vinous fermentation speedily
commences, and the liquid becomes converted into beer. This is what
actually takes place in the process of brewing, and the scientific brewer
endeavours to employ a proper quantity of ferment to decompose the whole
of the saccharine matter of his wort; but, at the same time, as equally
endeavours to avoid the use of an excess.
The chief product of the vinous fermentation is alcohol, but there are
other substances simultaneously produced, and which remain associated with
the fermented liquor. Among the principal of these are œnanthic acid,
œnanthic ether, fusel oil (oil of potato spirit, oil of grain), &c.; none
of which exist previously to fermentation, and are generally supposed to
result from the action of the nitrogenised matters of the solution on the
sugar. Under certain circumstances these extraneous products are formed in
much larger quantities than under others; and as these substances injure
the value of the alcohol with which they are associated, a knowledge of
the peculiar circumstances favourable and unfavourable to their production
is a desideratum to the brewer and distiller.
According to MM. Colin and Thénard, Frémy, Rousseau, and others, the
essential condition of a ferment, to be able to excite the pure vinous
fermentation, is to be sufficiently acidulous to act on coloured
test-paper; and this acidity should arise from the presence of certain
vegetable acids and salts, capable of conversion into carbonic acid and
carbonates by their spontaneous decomposition. Those acids and salts which
are found to pre-exist in fermentable fruits and liquors, as the tartaric,
citric, malic, and lactic acids, and their salts should be chosen for this
purpose; preference being given to the bitartrate of potassa, on account
of its presence in the grape. The addition of any of these substances to a
saccharine solution renders its fermentation both more active and
complete. The favorable influence of cream of tartar on fermentation was
first pointed out by Thénard and Colin, and the addition of a little of
this article has been adopted in practice, with manifest advantage, by the
manufacturers of British wine.
There is good reason for supposing that each variety of sugar which is
susceptible of the alcoholic fermentation is first converted into grape
sugar by contact with the ferment, and that this variety of sugar is alone
capable of yielding carbonic acid and alcohol.
The circumstances most favorable to this fermentation are, a certain
degree of warmth, a sufficient quantity of active ferment, and its due
distribution through the liquor. The temperature of from 68° to 77° Fahr.
is usually regarded as the most propitious for the commencement and
progress of fermentation; but it has been ably shown by Liebig that, at
this temperature, the newly formed alcohol slowly undergoes the ‘acetous
fermentation,’ forming vinegar, by which the vinous character of the
liquor is lessened. This conversion of alcohol into vinegar proceeds most
rapidly at a temperature of 95° Fahr., and gradually becomes more languid,
until, at about 46° to 50° Fahr. (8 to 10 Cent.), it ceases altogether,
while the tendency of the nitrogenous substances to absorb oxygen at this
low temperature is scarcely diminished in a perceptible degree. “It is
therefore evident that if wort (or any other saccharine solution) is
fermented in wide, open, shallow vessels, as is done in Bavaria, which
afford free and unlimited access to the atmospheric oxygen, and this in a
situation where the temperature does no exceed 46° to 50° Fahr., a
separation of the nitrogenous constituents, _i. e._ the exciters of
acidification, takes place simultaneously on the surface, and within the
whole body of the liquid.” (Liebig.) By this method wine or beer is
obtained, which is invariably far superior in quality to that fermented in
the usual manner. See FERMENTATION.
The symptoms of a perfect fermentation of malt wort, according to the
usual English system with top yeast (_oberhefe_), have been thus described
by a well-known practical writer on brewing: 1. A cream-like substance
forms round the edges of the gyle tun, which gradually extends itself, and
ultimately covers the whole surface of the liquor. 2. A fine curly or
cauliflower head in a similar way extends itself over the surface, and
indicates to the experienced brewer the probable quality of the
fermentation. 3. The ‘stomach,’ or ‘vinous odour,’ is next evolved, and
continues to increase with the attenuation of the wort. The peculiar
nature of this odour is also an indication of the state of the
fermentation.——4. The cauliflower head changes, or rises to a fine ‘rocky’
or ‘yeasty’ head, and ultimately falls down.——5. In this stage the head
assumes a peculiar ‘yeasty’ appearance, called by brewers ‘close-yeasty,’
and the gas is evolved in sufficient quantity to blow up little bells or
bubbles, which immediately burst, and are followed by others, at intervals
depending on the activity and forwardness of the fermentation. These bells
should be bright and clear; as, if they appear opaque or dirty, there is
something the matter with the wort. (Black.)
It is often of the utmost importance to brewers, wine merchants, sugar
refiners, druggists, &c., to be able to lessen the activity of the vinous
fermentation, or to stop it altogether, or to prevent its accession to
syrups and other saccharine and vegetable solutions. Whatever will still
the motion of the molecules of the nitrogenous matter forming the ferment
will render them inoperative as exciters of fermentation. Among the
simplest means of effecting this object, and such as admit of easy
practical application, may be mentioned exposure to either cold or heat.
At a temperature below about 50° Fahr., the acetous fermentation is
suspended, and the alcoholic fermentation proceeds with diminished
activity as the temperature falls, until at about 38° Fahr. it ceases
altogether. In like manner, the rapid increase of the temperature of a
fermenting liquid arrests its fermentation, and is preferable to the
action of cold, as it is of easier application, and perfectly precipitates
the ferment in an inert state. For this purpose a heat of about 180° Fahr.
is sufficient: but even that of boiling water may be employed with
advantage. In practice fluids are commonly raised to their boiling point
for this purpose, or they are submitted to the heat of a water bath
(207-1/2° Fahr.). In this way the fermentation of syrups and vegetable
solutions and juices is commonly arrested in the pharmaceutical
laboratory.
Among substances that may be added to liquids to arrest fermentation the
most active are——the volatile oil of mustard, coarsely powdered mustard
seed, or pure flour of mustard, sulphurous acid or the fumes of burning
sulphur, sulphuric acid, sulphite of lime, tincture of catechu, strong
spirit, strong acetic acid, chlorate of potassa, sugar of milk, bruised
horseradish, garlic, and cloves, and their essential oils, and all the
other volatile oils that contain sulphur, and most of the salts that
readily part with their oxygen. These substances arrest fermentation by
rendering the yeast inoperative, and they possess this power nearly in the
order in which they stand above. In practice, mustard, the fumes of
burning sulphur, sulphite of lime, and chlorate of potassa, are those most
adapted for beer, cider, wines, syrups, &c.; but some of the others are
occasionally used, though less active. For arresting or preventing the
fermentation of the vegetable juices and solutions, and the medicated
syrups employed in pharmacy, mustard seed, either alone or combined with a
little bruised cloves, may be safely used, as the addition of acids or
salts would lead to the decomposition of their active principles. For this
reason such liquids should be kept in a sufficiently low temperature to
prevent fermentation; and should they pass into that state it should be
preferably arrested by the application of heat or cold, as above
explained. Sugar of milk is also very effective for certain syrups, if not
all of them.
To prevent, or rather to lessen, the production of fusel oil, it has been
proposed to add a certain quantity of tartaric acid or bitartrate of
potassa to the wort, or to arrest the fermentative process somewhat before
the liquid has reached its utmost degree of attenuation. The best means of
depriving the spirit of this and other substances of a similar nature is
to largely dilute it with water, and to redistil it at a gentle heat.
Agitation with olive oil, decantation, dilution with a large quantity of
water, and redistillation, have also been recommended. An excellent method
is filtration through newly burnt and coarsely powdered charcoal. This
plan succeeds perfectly with moderately diluted spirit. On the Continent,
the addition of about 10% of common vinegar, and a very little sulphuric
acid, followed by agitation, repose for a few days, and redistillation is
a favourite method. A solution of chloride of lime is also employed for
the same purpose, and in the same way. In both these cases a species of
ether is formed, which possesses a very agreeable odour. In the first,
acetate of oxide of amyl (essence of jargonelle) is produced; and in the
other, chloride of amyl, which also possesses a pleasant ethereal smell
and taste. The affinity of the hydrated oxide of amyl (fusel oil) for
acetic acid is so great, that they readily unite without the intervention
of a mineral acid. (Doebereiner). Thus, the oil of vitriol mentioned
above, though always used in practice, might be omitted without any
disadvantage.
According to Messrs Bowerbank, the distillers quoted by Dr Pereira, 500
galls. of corn-spirit yield about one gall. of corn-spirit oil. See
ACETIFICATION, ALCOHOL, BREWING, DISTILLATION, FERMENTATION, FUSEL OIL,
SPIRIT, VINEGAR, VISCOUS FERMENTATION, YEAST, &c.
=VI′OLET.= _Syn._ PURPLE VIOLET, SWEET V.; VIOLA (Ph. L. & E.), L. “The
recent petals of _Viola odorata_, Linn.” (Ph. L.) It is chiefly used on
account of its colour. See SYRUP.
=VIOLET DYE.= Violet, like purple, is produced by a mixture of red and
blue colouring matter, applied either together or in succession. The
‘aniline colours’ are now almost exclusively used for obtaining violet on
silk and wool (see ANILINE, PURPLE, and TAR COLOURS). With the old dye
stuffs, violet may thus be obtained:——A good violet may be given to silk
or wool by passing it first through a solution of verdigris, then through
a decoction of logwood, and, lastly, through alum water. A fast violet may
be given by first dyeing the goods a crimson with cochineal, without alum
or tartar, and, after rinsing, passing them through the indigo
vat.——Linens and cottons are first galled with about 18% of gall-nuts,
next passed through a mixed mordant of alum, iron liquor, and sulphate of
copper, working them well, then through a madder bath made with an equal
weight of root, and, lastly, brightened with soap or soda. Another good
method is to pass cloth, previously dyed Turkey red, through the blue vat.
Wool, silk, cotton, or linen, mordanted with alum and dyed in a logwood
bath, or a mixed bath of archil and Brazil, takes a pretty, but false,
violet.
=VIS′COUS FERMENTATION.= _Syn._ MUCILAGINOUS FERMENTATION, MUCOUS F. The
peculiar change by which sugar, in solution, is converted into gummy
matters, and other products, instead of into alcohol.
When the expressed juice of the beet is exposed to a temperature of 90° to
100° Fahr., for a considerable time, the sugar it contains suffers this
peculiar kind of fermentation. Gases are evolved which are rich in
hydrogen, instead of being exclusively carbonic acid, and when the sugar
has, for the most part, disappeared, mere traces of alcohol are found in
the liquid, but, in place of that substance, a quantity of lactic acid,
mannite, and a mucilaginous substance, resembling gum Arabic, and said to
be identical with gum in composition. By boiling yeast or the gluten of
wheat in water, dissolving sugar in the filtered solution, and exposing it
to a tolerably high temperature, the viscous fermentation is set up, and a
large quantity of the gummy principle generated, along with a ferment of a
globular texture, like that of yeast, but which is capable of producing
only the viscous fermentation, in saccharine solutions.
The peculiar cloudy, stringy, oily appearance of wine and beer, called by
the French ‘graisse,’ and the English ‘ropiness,’ depends on the accession
of the viscous fermentation. The mineral acids and astringent substances,
especially the sulphuric and sulphurous acids, and tannin, precipitate the
viscous ferment, and are, hence, the best cures for this malady of
fermented liquors. It is the large amount of tannic acid in the red wines
and well-hopped beer which is the cause of their never being attacked with
‘graisse,’ or ‘ropiness.’ See VINOUS FERMENTATION, WINES, &c.
=VI′′SION.= The following means of preserving and restoring the sight may
be appropriately inserted here:——
For NEAR-SIGHTEDNESS.——Close the eyes and press the fingers very gently,
from the nose outward, across the eyes. This flattens the pupil, and thus
lengthens or extends the angle of vision. This should be done several
times a day, or at least always after washing the face, until
shortsightedness is overcome.
For LOSS OF SIGHT BY AGE, such as require magnifying glasses, pass the
fingers or towel from the outer corners of the eyes inwardly, above and
below the eyeballs, pressing very gently against them. This rounds them
up, and preserves or restores the sight.
It is said that many persons, by this last means, have preserved their
sight so as to read fine print at 80 years of age; others, whose sight has
been impaired by age, by carefully manipulating the eyes with their
fingers, from their external angles inwardly, have restored their sight,
and been able to dispense with glasses, and have since preserved it by a
continuance of the practice. To be successful, or safe, these practices
must be applied with great gentleness and caution. Many persons seriously
damage their eyes by forcibly rubbing them when drowsy, especially on
awaking in the morning.
The ‘Lancet’ remarks, that “there is good reason to believe that chicory
(the coffee of the Londoners), from its narcotic character, exerts an
injurious effect on the nervous system. So convinced of this is Professor
Beer, of Vienna, a most celebrated German oculist, that he has enumerated
chicoried coffee among the causes of amaurotic blindness.”
To strengthen the eyes, to relieve them when swollen or congested, and to
remove chronic ophthalmia, purulent discharges, &c., nothing is equal to
frequently bathing them with water, at first tepid, but afterwards lowered
in temperature to absolute coldness.
=VIT′RIOL.= A common name for sulphuric acid and for several of its salts.
(See _below_.)
=Vitriol, Blue.= _Syn._ ROMAN VITRIOL. Commercial sulphate of copper.
=Vitriol, Green.= Commercial sulphate of iron.
=Vitriol, White.= Commercial sulphate of zinc.
=VITTIE VAYR.= _Syn._ VETIVER. The Tamool name of the odorous and fibrous
roots of the _Andropogon muricatus_ sold by the perfumers.
=VOLTA′IC ELECTRICITY.= _Syn._ GALVANIC E., GALVANISM, VOLTAISM. That
branch of electrical science which has reference to the phenomena
attendant on the development of electricity by chemical action.
Electricity thus developed may be made to show itself in the ‘static’
condition, so as to produce the effects of frictional electricity, but it
is much more easily obtained in the ‘dynamic’ condition——in other words,
as a ‘voltaic current’——when it is especially remarkable for its chemical
and magnetic effects. If a plate of zinc and a plate of platinum be
immersed in dilute sulphuric acid, and connected outside the liquid by a
wire, a current of electricity will immediately be set up, and will
continue as long as the conducting circuit is complete and the action of
the acid on the zinc goes on. The current of ‘positive’ electricity passes
from the zinc, through the liquid, to the platinum, and thence through the
wire to the zinc. The arrangement of two dissimilar metals immersed in a
liquid which acts upon one of them is called a voltaic couple. By uniting
a number of couples together in regular order, a voltaic pile or battery
is formed.
The older forms of the voltaic battery, viz., VOLTA’S PILE, CRUIKSHANK’S
TROUGH, and WOLLASTON’S BATTERY, are now but little used. They all consist
of a series of couples of zinc and copper, excited by an acid liquid,
generally a mixture of water with 1/40th of its bulk of sulphuric acid,
and 1/60th of nitric acid.
[Illustration:
_A._ A copper cylinder, filled with a saturated solution of sulphate of
copper.
_B._ A smaller porous cylinder (earthenware or membrane), containing a
mixture of 1 measure of strong sulphuric acid, and about 8 measures of
water.
_C._ A rod of amalgamated zinc, supported in the smaller cylinder by the
cross-piece (_i_).
_D._ A shelf full of small holes, for supporting crystals of sulphate of
copper, to keep up the strength of the solution.
_e_ and _f._ Screws and caps to connect the wires _g_ and _h_ with the
battery.
_g._ The negative wire, connected with the zinc.
_h._ The positive wire, connected with the copper.]
One of the most useful forms of the voltaic battery is that proposed by
the late Prof. Daniell, and commonly known by his name. Its peculiar
advantages arise from its action continuing without interruption for a
long time; hence the name of ‘constant battery’ that has been applied to
it. The foregoing figure will explain the construction of each couple.
One of these couples is sufficient for electro-typing; six of them form a
circle of considerable power, and about 20 produce one sufficiently strong
for most experiments of demonstration and research.
In arranging these, as well as other batteries, when intensity, or
travelling power, is desired, the metallic communication is made between
the opposite metals (the zinc of one couple being united with the copper
of another); but when simple quantity without intensity is required, the
zinc of one battery is united with the zinc of the other, and the copper
of the one with the copper of the other——an effect which is equally
attainable with a single battery of enlarged dimensions.
Another useful apparatus is GROVE’S BATTERY, in which the positive metal
consists of amalgamated zinc immersed in sulphuric acid, diluted with 10
times its bulk of water; and the negative metal of platinum immersed in
strong nitric acid. The two liquids are kept separate by the use of porous
vessels, as in ‘Daniell’s battery.’ This is an extremely powerful
arrangement, but not so constant as Daniell’s, owing to the reduction of
the nitric acid to lower oxides of nitrogen. After this battery has been
in action for about an hour, copious red nitrous fumes are given off,
which cause great annoyance.
In place of platinum, compact charcoal or coke, prepared by a rather
troublesome process, may be used, and the arrangement then constitutes a
BUNSEN’S BATTERY. Other substitutes for the costly platinum have been
proposed, as lead coated with gold or platinum, and iron rendered
‘passive’ by immersion in strong nitric acid. Callan has obtained very
good results with amalgamated zinc and cast iron immersed in diluted
sulphuric acid, without the use of nitric acid (MAYNOOTH BATTERY).
In SMEE’S BATTERY, which is much used in the arts, pairs of amalgamated
zinc and platinised silver (or platinised platinum) are immersed in dilute
sulphuric acid (1 part acid to 7 parts water). The plates of zinc are
usually bent double, and the platinised plates interposed between the two
surfaces formed by the bend. See PLATINISING (p. 1337).
In every voltaic combination the passage of the electricity (_i. e._ the
positive modification of the force) in the liquid is from the active
element to the inactive element; in the case of a simple zinc-and-copper
couple, for instance, it is from the zinc to the copper. If this simple
fact be borne in mind, it will decide in every case the question which
confuses so many, namely, which is the positive, and which the negative
end of a battery? The positive is the end where the electricity leaves the
battery; the negative where it re-enters it. For further information
connected with the subject of voltaic electricity, see articles on
ELECTRICITY, ELECTROLYSIS, ELECTROTYPE, ETCHING, &c.
=VOLUME′TRIC ANALYSIS.= Quantitative chemical analysis by measure. This
method of analysis “consists in submitting the substance to be estimated
to certain characteristic reactions, employing for such reactions liquids
of known strength, and from the quantity of the liquid employed
determining the weight of the substance to be estimated by means of the
known laws of equivalence.” As an example of this method we give the
following from the Introduction in Mr Sutton’s excellent ‘Handbook of
Volumetric Analysis,’——“Suppose that it is desirable to know the quantity
of pure silver contained in a shilling. The coin is first dissolved in
nitric acid, by which means a bluish solution, containing silver, copper,
and probably other metals, is obtained. It is a known fact that chlorine
combines with silver in the presence of other metals to form chloride of
silver, which is insoluble in nitric acid. The proportions in which the
combination takes place are 35·46, of chlorine to every 108 of silver;
consequently, if a standard solution of pure chloride of sodium is
prepared by dissolving 58·46 grains of the salt (_i. e._ 1 equiv. sodium =
23, 1 eq. chlorine = 35·46 = 1 eq. chloride of sodium 58·46) in so much
distilled water as will make up exactly 1000 grains by measure; every
single grain of this solution will combine with ·108 grain of pure silver
to form chloride of silver, which precipitates to the bottom of the vessel
in which the mixture is made. In the process of adding the salt solution
to the silver, drop by drop, a point is at last reached when the
precipitate ceases to form. Here the process must stop. On looking
carefully at the graduated vessel from which the standard solution has
been used, the operator sees at once the number of grains which have been
necessary to produce the complete decomposition. For example, suppose the
quantity used was 520 grains; all that is necessary to be done is to
multiply ·108 grain by 520, which shows the amount of pure silver present
to be 56·16 grains.” The volumetric method is much less troublesome than
the ordinary method of analysis (by separating the constituents of a
mixture and weighing them), and is admirably adapted for the examination
of substances used in arts and manufactures. Most of the processes
described under ACIDIMETRY and ALKALIMETRY are examples of this method.
See those articles, also EQUIVALENTS, TEST SOLUTIONS, &c.
=WADE’S DROPS.= Compound tincture of benzoin.
=WA′FER PAPER.= See WAFERS, in Cookery (_below_).
=WA′FERS.= Thin adhesive discs, used for securing letters or sticking
papers together.
_Prep._ 1. (WAFERS, FLOUR W.) The finest; wheaten flour is mixed with
water, either pure or coloured, to a smooth pap or batter, which, after
being passed through a sieve, to remove clots or lumps, is poured into the
‘wafer-irons’ (previously warmed and greased with butter or olive oil),
and in this state exposed to the heat of a clear charcoal fire; the whole
is then allowed to cool, when the irons are opened, and the thin cake,
which has become hard and brittle, is cut into wafers by mean of sharp
annular steel punches made exclusively for the purpose.
2. (GELATINE WAFERS, TRANSPARENT W.) Good gelatine or glue is dissolved,
by the heat of a water bath, in just sufficient water to form a consistent
mass on cooling; it is then poured, whilst hot, upon the surface of a warm
plate or mirror glass, slightly oiled, and surrounded with a border of
card paper (laid flat); a similar plate, also warmed and oiled, is next
laid upon the gelatine, and the two plates pressed into as close contact
as is permitted by the card paper; when quite cold the thin sheet of
gelatine is removed, and cut into wafers with punches, as before. 1 to 2
oz. of sugar is commonly added to each lb. of gelatine.
3. (MEDALLION WAFERS.) A sheet of metal or glass, having designs sunk in
it corresponding to the raised part of seals, being provided, the hollows
are filled up with a mixture formed of any appropriate coloured powder,
made into a paste with gum water or size, leaving the flat part clear;
melted coloured glue is then poured on the plate, and the process is
otherwise conducted as before. For use, the paper is wetted where the
wafer is to be applied.
_Obs._ Care must be taken that no poisonous colours be employed. For
gelatine wafers, transparent colours only can be used. Those noticed under
LIQUEURS and STAINS (Confectioner’s) are appropriate. To these may be
added plumbago, sesquioxide of iron (crocus martis), smalts, levigated
vegetable charcoal, and vermilion.
=Wafers.= (In Cookery.) _Prep._ Make fine flour, dried and sifted, into a
smooth thin batter with good milk, or a little cream-and-water; add about
as much white wine as will make it thick enough for pancakes, sweeten it
with a little loaf sugar, and flavour it with powdered cinnamon. When thus
prepared have the wafer-irons made ready, by being heated over a charcoal
fire; rub them with a piece of linen cloth dipped in butter; then pour a
spoonful of the batter upon them, and close them almost immediately; turn
them upon the fire, and pare the edges with a knife, if any of the batter
oozes out. A short time will bake them, when the irons are perfectly
heated. The wafers must be curled round whilst warm when they are for
ornaments. ‘Wafer paper’ is prepared in a similar way to the above; but
when intended to be kept for some time, the milk must be omitted. Used by
cooks, &c.; and, recently, as an envelope for nauseous medicines.
=Wafers, Da Silva’s.= These nostrums were introduced to the public some
time ago, as though they were prepared from the formulæ of a celebrated
physician whose name was affixed to them.[256] There are three varieties,
which are said to be prepared as follows:
[Footnote 256: For an exposition of the Da Silva quackery, with Or
Locock’s letter on the subject, see the ‘Anat. of Quackery,’ or the ‘Med.
Cir.,’ ii, 106-126.]
1. APERIENT OR ANTIBILIOUS WAFERS. From sugar and extract of liquorice
(Spanish juice), equal parts; senna and jalap, of each in fine powder,
about 1/2 dr. to every oz. of sugar employed; made into a mass with a
concentrated infusion of senna, and divided into 12-gr. lozenges or
squares with the corners rounded off.
2. FEMALE WAFERS. From sugar, horehound candy (or honey), and aperient
wafer mass, equal parts; beaten to a proper consistence with weak gum
water, to which a little orange-flower water has been added, and divided
into 8 gr. tabellæ, as before.
3. PULMONIC WAFERS. From lump sugar and starch, of each in powder, 2
parts; powdered gum, 1 part; made into a lozenge-mass with vinegar of
squills, oxymel of squills, and ipecacuanha wine, equal parts, gently
evaporated to 1-6th their weight, with the addition of lactucarium in the
proportion of 20 to 30 gr. to every oz. of the dry powders, the mass being
divided into half-inch squares, weighing about 7-1/2 gr. each (when dry),
as before.
=WAL′NUT.= The _Juglans regia_, a tree of the natural order _Juglandaceæ_.
The sap yields sugar; the fruit is the walnut; the kernels of the latter
are eaten and pressed for their oil; the peel or husks are used for
‘rooting’ or dyeing brown; the unripe fruit is pickled, and its juice is
used as a hair dye; the leaves are reputed diaphoretic and antisyphilitic;
and the wood is esteemed for cabinet work.
=WARBURG’S FEVER DROPS.= See TINCTURE, WARBURG’S FEVER.
=WARD’S RED DROP.= A strong solution of emetic tartar in wine.
=WARTS.= _Syn._ VERRUCÆ, L. These chiefly attack the hands, and may be
removed by the daily use of a little nitrate of silver, nitric acid, or
aromatic vinegar, as directed under CORNS. The first of the above
applications produces a black stain, and the second a yellow one; both of
which, however, wear off after the lapse of some days. Acetic acid
scarcely discolours the skin. Erasmus Wilson, the eminent surgeon and
talented author of several works on the skin, mentions the case of a
gentleman who removed an entire crop of warts from his knuckles and
fingers by subjecting them to a succession of sparks from one of the poles
of an electrical machine. “He was in the habit, as is usual, of trying the
amount of electric fluid collected in his machine by placing his knuckle
near the brass knob, and receiving a spark. Observing that an odd
sensation was produced whenever the spark struck a wart, he was tempted
for amusement to give them a round of discharges. When his attention was
next directed to his hands he found, to his surprise and satisfaction,
that all the warts had disappeared.” Dr Peez, of Wiesbaden, recommends the
internal use of carbonate of magnesia in cases of warts.
The papular eruption which covers the hands of some persons, and which is
occasionally called ‘soft warts,’ is best removed by the daily use of
Gowlard’s lotion.
=WASH.= The fermented wort of the distiller.
=WASH-BALLS.= See SAVONETTES.
=WASH-BOTTLE.= The principle of this very common and indispensable
laboratory utensil, by which precipitates are washed, will be readily
understood by reference to No. 1 of the engravings below.
The bottle being two thirds filled with distilled waters by blowing into
the shorter tube, _b_, a small jet of water is forced through the nozzle
of the longer tube, _c_. We give the following directions for the
construction of a WASH-BOTTLE, from Mr Clowes’ excellent little manual,
entitled ‘An Elementary Treatise on Practical Chemistry,’[257]——“A thin,
flat-bottomed flask is chosen, of 16 or 18 ounces capacity; the neck must
not be less than an inch in diameter. Procure a sound cork, which is
slightly too large to enter the neck, soften the cork by placing it upon
the floor and rolling it backwards and forwards under the foot with gentle
pressure; when thus softened the cork must fit tightly into the
flask.[258] Two pieces of glass tubing rather longer than would be
required for the tubes _a_ and _b_ are then bent into the form shown in
Fig. 1. The ends of the tubes are, if necessary, cut off to the right
length, and their sharp edges rounded by holding them in the Bunsen flame,
or the tip of the blowpipe flame.
[Footnote 257: J. and A. Churchill, New Burlington Street.]
[Footnote 258: “A vulcanized india-rubber stopper is much more durable for
this and most other chemical processes. It is perforated by a sharp,
well-wetted cork bore, or by a wetted round file.”]
[Illustration: FIG. 1, FIG. 2. and FIG. 3.]
“Two parallel holes are then bored in the cork by means of a round file,
or by a proper size cork-borer: the holes must be rather smaller than the
glass tubes, and must not run into one another, or to the outside of the
cork. They are slightly enlarged, if necessary, by the round file. Into
these holes the tubes _a_ and _b_ are then pushed with a twisting motion;
if the holes have been made of the proper size the tubes must enter
somewhat stiffly, but without requiring much pressure. Upon the upper end
of a is fitted a small piece of india-rubber tubing, about an inch and a
half in length, and into the other end of this is a finished short jet
(_c_) made by drawing out a piece of glass tubing in the flame; its nozzle
may be constructed, if necessary, by holding it perfectly dry in the flame
for some time. The neck of the bottle should then be bound round with
twine, like the handle of a cricket-bat, or tightly covered with a piece
of flannel. This prevents the fingers from being burnt when the bottle
contains boiling water.”
We append below some varieties of washing bottles. The round-bottomed are
in more general requisition than the flat-bottomed description; although
this latter presents the advantage of standing more firmly, and, if
boiling water be required, of furnishing it more quickly than the bottle
with the round base.
In some laboratories earthenware bottles are in use. These are not so
easily broken as those made of glass, but, unlike these latter, water
cannot be boiled in them, neither can we see whether they be full or
empty.
=WASHERWOMAN’S SCALL.= See PSORIASIS.
=WASHES.= The familiar name of lotions, more especially of those employed
as cosmetics. See FRECKLES, LOTION, MILK OF ROSES, SKIN COSMETICS, &c.,
and the following page.
=Washes, Hair.= _Prep._ 1. From rosemary tops, 2 oz.; boiling water, 1
pint; infused together in a teapot or jug, either with or without the
addition of rectified spirit, 1 fl. oz. (or rum, 2 fl. oz.) to the cold
strained liquor.
2. Box leaves, a small handful; boiling water, 1 pint; digest for an hour,
simmer 10 minutes, and strain. Both are used to improve the growth of and
to strengthen the hair.
3. To clean the ‘partings,’ remove scurf, &c.——_a._ (ANTIPITYRIENNE.) From
sesquicarbonate of ammonia, 1 oz.; spirit of rosemary, 1/2 pint; rose of
elder-flower water, 1-1/2 pint.
_b._ (DETERGENT ESSENCE.) From honey, 2 oz.; borax, 1 oz.; cochineal
(bruised), 1/4 oz.; camphor, 1 dr.; (dissolved in) rectified spirit, 2 fl.
oz.; soft water, 3/4 pint; oil of rosemary, 20 drops.
_c._ (VEGETABLE EXTRACT.) Take of salt of tartar, 1 oz.; rosemary water, 1
pint; burnt sugar, q. s. to tinge it brown; dissolve, filter, and add of
essence of musk, 10 drops.
4. To darken the hair.——_a._ From pyrogallic acid, 1/4 oz.; distilled
water, orange-flower water, and rectified spirit, of each 1-1/4 fl. oz.
_b._ (LA FOREST’S COSMETIC LOTION or LIQUID HAIR DYE.) Boil, for a few
minutes, chloride of sodium, 1 dr., and sulphate of iron, 2 dr., in red
wine, 1 lb.; then add of verdigris, 1 dr.; in 2 or 3 minutes remove it
from the fire, and further add of powdered galls, 2 dr.; the next day
filter. For use, moisten the hair with the liquid; in a few minutes dry it
with a cloth, and afterwards wash the skin with water.
5. To prevent the hair falling off.——_a._ (AMERICAN SHAMPOO LIQUID.) Take
of carbonate of ammonia, 1/2 oz.; carbonate of potash, 1 oz.; water, 1
pint; dissolve, and add the solution to a mixture of tincture of
cantharides, 5 fl. oz.; rectified spirit, 1 pint; good rum, 3 quarts. Used
to strengthen the hair and to remove dandruff, by moistening it with the
mixture, rubbing so as to form a lather, and then washing with cold water.
_b._ (BALM OF COLUMBIA.) As the last, omitting the potash, quadrupling the
carbonate of ammonia, and adding some perfume.
_c._ (Eras. Wilson.) Eau de Cologne (strongest), 8 fl. oz.; tincture of
cantharides, 1 fl. oz.; oils of rosemary and lavender, of each 1/2 fl. dr.
_d._ (Dr LOCOCK’S LOTION.) From expressed oil of mace (nutmeg), 1 oz.,
liquefied, at a gentle heat, with olive oil, 1/2 oz.; and, when cold,
formed into an emulsion by agitation, with rose water, 1/4 pint; spirit of
rosemary, 2-1/2 fl. oz.; stronger liquor of ammonia, 1-1/2 fl. dr. For
other formulæ, see BALDNESS, HAIR DYES, LOTION, &c.
=Washes, Medicinal.= See LOTION, &c.
=Washes, Mouth.= _Syn._ TOOTH WASHES; COLLUTORIA, L. _Prep._ 1. Take of
camphor (cut small), 1/4 oz.; rectified spirit, 2 fl. oz; dissolve. A few
drops to be added to a wine-glassful of water, to sweeten the breath and
preserve the teeth.
2. Chloride of lime, 1/2 oz.; water, 2 fl. oz.; agitate well together in a
phial for 1/2 an hour, filter, and add, of rectified spirit, 2 fl. oz.;
rose or orange-flower water, 1 fl. oz. Used, highly diluted with water, as
the last, by smokers and persons having a foul breath.
3. Mastic (in powder), 2 dr.; balsam of Peru, 1/2 dr.; gum, 2 dr., or
q. s.; orange-flower water, 6 fl. oz.; tincture of myrrh, 2 fl. dr.; for
an emulsion. In loose teeth, &c.
4. Tannin, 1/2 dr.; tincture of tolu, 2 fl. dr.; tincture of myrrh, 6 fl.
dr.; spirit of horseradish, 2 fl. oz.; mix. In spongy gums, scurvy, &c.;
diluted with tepid water.
5. (Swediaur.) Borax, 1/4 oz.; water and tincture of myrrh, of each 1 fl.
oz.; honey of roses, 2 oz. In tender or ulcerated gums.
6. Balsam of Peru, 2 dr.; camphor, 1/2 dr.; essence of musk and liquor of
ammonia, of each 1/2 fl. dr.; tincture of myrrh, 3 fl. dr.; spirit of
horseradish, 1-1/2 fl. oz. To sweeten and perfume the breath; a
teaspoonful in 1/2 wineglassful of tepid water to rinse the mouth with.
=Washes for the Nose.= _Syn._ NASAL DOUCHES, COLLUNARIA. The following
formulæ medicinally employed for the purpose of washing or rinsing out the
nostrils are from the ‘Pharmacopœia of the Throat Hospital.’
In applying them it is directed that “not more than twenty ounces of fluid
should ever be used for a nasal douche, and ten ounces are generally
sufficient. If an apparatus on the syphon principle be applied, it should
be placed only just above the level of the patient’s head, in order to
avoid too great force of current. The temperature of the fluid should be
about 90° F.”
NASAL DOUCHE OF TANNIC ACID. _Syn._ COLLUNARIUM ACIDI TANNICI. _Prep._
Tannic acid, 3 grams; water, 1 oz.; dissolve.——_Use._ Astringent
NASAL DOUCHE OF ALUM. _Syn._ COLLUNARIUM ALUMINIS. _Prep._ Alum, 4 grams;
water, 1 oz.; dissolve.——_Use._ As a mild astringent.
NASAL DOUCHE OF PERMANGANATE OF POTASH. _Syn._ COLLUNARIUM POTASSÆ
PERMANGANATIS. _Prep._ Solution of permanganate of potash (B. P.), 6
minims. Water to 1 oz.; mix.——_Use._ Detergent.
NASAL DOUCHE OF QUININE. _Syn._ COLLUNARIUM QUINIÆ. _Prep._ Sulphate of
quinine, 1/2 grain; water, 1 oz. Dissolve by the aid of a gentle heat.
This solution is occasionally useful in hay-fever. It is generally
sufficient to place a little in the palm of the hand and draw it up
through the nose.
NASAL DOUCHE OF SULPHO-CARBOLATE OF ZINC. _Syn._ COLLUNARIUM ZINCI
SULPHO-CARBOLATIS. _Prep._ Sulpho-carbolate of zinc, 2 grams; water, 1
oz.; dissolve.——_Use._ Antiseptic.
=Washes, Tooth.= See _above_.
=WASHING (as applied in Chemistry).= In the chemical laboratory the
washing of precipitates is an operation of constant occurrence, and as the
accurate result of the quantitative analysis in which the process of
precipitation is had recourse to, essentially depends upon the manner in
which the washing has been carried out, we have thought it desirable in
the interest of the worker commencing practical chemistry to amplify under
the present section the remarks which occur under the article
‘Precipitation.’ In washing a precipitate the object is, of course, to
entirely free it from all extraneous matter, so as to ensure, after proper
drifting, its being weighed in an absolutely pure and uncontaminated
state. To arrive at a correct knowledge as to when a precipitate has been
properly washed, the operator must never trust to guesswork, but to
_ocular demonstration_, by testing a minute portion, such as a drop or so
of the washings, from time to time.
This may be done, either by adding——1. A very minute quantity of the
proper precipitant[259] to the washings; or——2. By evaporating a drop of
the latter on a platinum knife, or a piece of platinum foil; when, if in
the former case no turbidity is caused and in the latter no fixed residue
remain, the precipitate may be pronounced perfectly washed. The operator,
however, instead of not sufficiently washing his precipitate, is
frequently liable to fall into another dilemma, which consists not so much
in overwashing it as in washing it with an unsuitable liquid, or one in
which the precipitate is, to a greater or lesser extent, soluble.
[Footnote 259: See PRECIPITATE]
It may not unfrequently happen that the best available precipitant may be
one in which the precipitate is soluble to some small extent. Under these
circumstances, before throwing down the precipitate, the liquid should, as
far as practicable, be removed by evaporation.
Many precipitates which are not altogether insoluble in water may, by the
addition of some other liquid to the water, be rendered much less so.
Thus, the double chloride of platinum and ammonium which is incompletely
thrown down in water is perfectly precipitated if alcohol be added to the
water, as are also chloride of lead and sulphate of lime, whilst the basic
phosphate of magnesium and ammonium may be rendered insoluble in water by
the addition of ammonia to the water. The precipitate having subsided to
the bottom of the fluid in which it was suspended, the supernatant liquid
may be removed from it either by filtration or decantation. In some cases
both processes are had recourse to. To wash a precipitate which has been
separated by filtration, and which in a moist condition more or less fills
the paper-filter inserted in a proper funnel, the wash-bottle described
below is employed. In using this apparatus the jet of water that is made
to issue from the bottle should be denoted upon the sides of the filter,
and never in the centre, since this would cause a splashing and a
consequent loss of the precipitate. The same contingency would be liable
to follow it the waters were propelled too violently from the bottle. On
no account must the wash-water be allowed to reach to the top of the
filter. Another precaution to be guarded against is the formation in the
precipitate of fissures or channels; if these are not prevented, the water
will not permeate all the parts of the precipitate, and it will be only
very insufficiently washed. When such channels form, it will be best to
stir up the precipitates with a glass rod or a platinum spatula, taking
care, however, to avoid tearing or making a hole in the filter.
Precipitates that are washed by decantation ought to consist of such
substances as readily subside from the liquid in which they are suspended
and are practically insoluble in water, since a very much larger quantity
of this menstruum has to be employed than when filtration is had recourse
to. The process is generally carried out in deep vessels. The supernatant
liquid being removed, the vessel is filled up with water, and the
precipitate well stirred up with a glass rod; after it has again fallen
down fresh water is added, and the process is continued until the washings
cease to show the presence of any soluble matter. The several washings
being collected, are let stand some 12 or 24 hours; after which time,
should no precipitate show itself, they are thrown away. Should any
deposits form in the washing, it is carefully removed either by filtration
or decantation, and its amount being determined, the result is added to
that obtained from the bulk of the precipitate. Where the nature of the
precipitate is in no way influenced by hot water, this latter should
always be used in washing precipitates, as it greatly facilitates and
expedites the operation. Many precipitates require to stand a long time
before they entirely subside from the fluid in which they are suspended.
Most gelatinous, pulverulent, and crystalline precipitates are of this
nature. The separation of the precipitate should not be attempted until
after the liquid containing the precipitate has stood several hours.
=WASHING FLU′IDS.= Solutions of carbonate of soda, rendered caustic with
quicklime.
=WASHING POW′DERS.= See POWDERS.
=WATCH′FULNESS.= _Syn._ SLEEPLESSNESS. AGRYPNIA, L. The common causes of
watchfulness are thoughtfulness or grief, disordered stomach or bowels,
heavy and late suppers, and a deficiency of outdoor exercise. The best
treatment, in ordinary cases, simply consists in an attention to these
points. The method of producing sleep recommended by a late celebrated
hypnotist consists in merely adopting an easy recumbent position,
inclining the head toward the chest, shutting the eyes, and taking several
deep inspirations with the mouth closed. Another method, recommended by
an eminent surgeon, and which appears infallible if persevered in with
proper confidence, and which is suitable either to the sitting or
recumbent posture, consists in tying a decanter cork with a bright
metallic top, a pencil-case, or any other bright object on the forehead,
in such a position that the eyes must be distorted or strained to be
capable of seeing it. By resolutely gazing in this way for a short time,
without winking, with the mind fully absorbed in the effort, the muscles
of the eyes gradually relax, and the experimenter falls asleep. Gazing in
a similar manner on any imaginary bright spot in the dark, as at night,
exerts a like effect. A tumblerful of cold spring water, either with or
without a few grains of bicarbonate of potash in it, taken just before
lying down, will frequently succeed with the dyspeptic and nervous, when
all other means fail.
The following valuable advice to those who suffer from unnatural
wakefulness is abridged from the late Dr Tanner’s valuable work on the
‘Practice of Medicine.’[260]
[Footnote 260: ‘The Practice of Medicine,’ by Thos. Hawkes Tanner, M.D.,
Renshaw, London.]
As his starting point Dr Tanner enjoins the practice of taking a proper
amount of exercise daily. A digestible diet, such as is not liable to
cause acidity or flatulence, must also be adopted, and tea and coffee must
be abstained from in the after part of the day. Early dinners and light
suppers are also recommended. The reading of any thrilling work of fiction
previous to retiring to rest is also prohibited. The patient is advised to
seek his bed at an early and regular hour, and it is desirable to have his
sleeping chamber well ventilated, and if the weather be chilly the bedroom
fire should be lighted. Feather beds should be abandoned for mattresses;
there should not be too many blankets on the bed, the pillows should be
firm and high, and no curtains or hangings should be allowed. Should the
above means fail to produce the required sleep, before going to bed the
patient is advised to try a tumbler of port-wine negus, or of mulled
claret, or of white-wine whey, the last thing. The aged are recommended
(should the above methods be unsuccessful) to imbibe a glass of spirit and
water, which is said to be all the more effective if drunk when in bed. In
some cases, attended by a hot or dry skin, a glass of cold water has been
found useful. Another remedy is the use of a bath, for about three or five
minutes, just before getting into bed, at a temperature varying from 90°
to 96° F.
Rapid sponging of the body with tepid water is also recommended, as also
the use of a warm foot bath, at a temperature of 100° F., or of a
hot-water bottle in the bed, or putting the feet in cold water for a
minute, and then vigorously rubbing them.
For those whose sleeplessness is caused by their prosecuting literary
work till a late hour a short brisk walk, just before retiring to bed, is
recommended.
If the wakefulness can be traced to any bodily ailment, this, of course,
must be removed by the proper means. Constipation, which is not at all an
unfrequent cause of insomnia, must be combated by the methods described
under that article. If there be headache it will be best removed by
applying a rag dipped in cold water to the scalp, or a bladder containing
ice.
Should the adoption of any of the above suggestions fail all kinds of
mental labour and excitement during the day must be greatly diminished,
and physical exercise must replace them. Sedatives should be had recourse
to with great caution, and under medical supervision only. Because of the
hazard attending their use, and of the ready tendency their adoption has
to degenerate into a pernicious ineradicable habit, we have forebore to
specify the medicinal agents Dr Tanner prescribes for sleeplessness,
strongly recommending the patient, before he has recourse to them, to
exhaust the category of suggestions given by Dr Tanner, and, should these
unhappily be found to fail, and he is drawn to soporifics, we again
reiterate, let him take them only under medical supervision.
Another method, adopted by professional hypnotists, consists in gently
moving, in opposite directions, a finger of each hand over the forehead,
just above the eyebrows. A soothing and drowsy effect is said to be
thereby produced, which ends in tranquil slumber.
Dr Ainslie Hollis contributes some excellent hints on the treatment of
wakefulness to the practitioner. He classifies the treatment under two
heads——first, the induction of natural sleep, and, secondly, the
production of narcosis or artificial rest. The application of mustard
plasters to the abdomen generally brings about the first result,
producing, according to Schuler, first dilatation, and subsequently
contraction of the vessels of the pia mater. Dr Pleyer, of Jena, on the
supposition that sleep may be induced by the introduction of the fatigue
products of the body, advocates the administration of a solution of
lactate of soda. When sleeplessness is the result of brain exhaustion Dr
Hollis advocates a tumbler of hot claret negus. The alkalies and alkaline
earths, says the ‘Boston Journal of Chemistry,’ are useful when acid
dyspepsia is associated with the insomnia. In hot weather, sprinkling the
floor of the sleeping apartment with water lessens the irritant properties
of the air, adding much to the comfort of the sleepers; possibly the
quantity of ozone is at the same time increased. When sleep is broken by
severe pain, opium or morphia is of value, bringing not only relief, but
producing anæmia of the cerebral vessels; when neuralgia is the cause an
injection of morphia under the skin, near the branch of the affected
nerve, will have more effect than by administering it by the mouth.
Again, when wakefulness is due to defective cardiac power, digitalis may
be useful. Chloral hydrate is supposed to owe its hypnotic effect to its
power of diminishing the amount of blood in the brain, and therefore it
may be used when sleeplessness arises from the pains of muscular spasm.
The bromides, although undoubtedly sedatives, possess very doubtful
hypnotic properties. See SUPPER, &c.
=WA′TER.= H_{2}O. _Syn._ OXIDE OF HYDROGEN, PROTOXIDE OF H.; AQUA, L.;
EAU, Fr.; WASSER, Ger.; ὑδωρ, Gr. The ancients regarded water as a simple
substance, and as convertible into various mineral and organic products.
Earth, air, fire, and water were at one time conceived to be the
elementary principles or essences of matter from which all form and
substance derived their existence. The true constitution of water was not
discovered until about the year 1781, when Cavendish and James Watt,
independently and nearly simultaneously, showed it to be a compound of
hydrogen and oxygen. Five years, however, before this time (1776), the
celebrated Macquer, assisted by Sigaud de la Fond, obtained pure water by
the combustion of hydrogen in the air. It has since been satisfactorily
demonstrated that hydrogen and oxygen exist in water in the proportion of
1 to 8 by weight, or 2 to 1 by volume; the sp. gr. of hydrogen being to
that of oxygen as 1 to 16. One cubic inch of perfectly pure water at 62°
Fahr., and 30 inches of the barometer, weighs 252·458 gr.; by which it
will be seen that it is 770 times heavier than atmospheric air. Its sp.
gr. is 1·0, it being made the standard by which the densities of all solid
and liquid bodies are estimated. The sp. gr. of frozen water (ice) is
·9175, water being 1·0 (Dufour); that of aqueous vapour (steam), ·6252,
air being 1·0. Water changes its volume with the temperature; its greatest
density is about 39-1/2° Fahr., and its sp. gr. decreases from that point,
either way. Water is nearly incompressible. By subjecting water to a
pressure of 705 atmospheres, Cailletet found the compressibility to be at
the rate of ·0004451 for each atmosphere. Water evaporates at all
temperatures; but at 212° under ordinary circumstances, this takes place
so rapidly that it boils, and is converted into vapour (steam), whose bulk
is nearly 1700 times greater than that of water.
_Var._ Of these the following are the principal:
DISTILLED WATER; AQUA DESTILLATA (B. P., Ph. L., E., & D.), L. Obtained by
the distillation of common water through a block-tin worm, rejecting the
first and last portions that come over. The still employed for this
operation should be used for no other purpose; and when great nicety is
required, the distillation should be performed in glass or earthenware. It
remains limpid on the addition of lime water, chloride of barium, nitrate
of silver, oxalate of ammonium, or hydrosulphuric acid. It is the only
kind of water that should be employed in chemical and pharmaceutical
operations. When distilled water is not at hand, clean filtered or
clarified rain water is the only kind that can be successfully
substituted.
NATURAL WATERS. In respect of wholesomeness, palatability, and general
fitness for drinking and cooking, natural waters may be classified in
orders of excellence as follows (‘Rivers Pollution Commissioners’ Sixth
Report’):——
{1. Spring water } Very palatable.
_Wholesome_ {2. Deep-well water }
{3. Upland surface water } Moderately palatable.
{4. Stored rain water }
_Suspicious_ {5. Surface water from cultivated lands }
{6. River water to which sewage gains } Palatable.
_Dangerous_ { access }
{7. Shallow well water }
The average composition of the four classes of unpolluted waters is given
by the same authorities as follows. Their estimations are in parts per
100,000, but may be converted in grains per gallon by multiplying by 7 and
dividing by 10:
--------------+------+-------+--------+-----+--------+--------
| | | | |Nitrogen|Total
|Total |Organic|Organic |Ammo-| as |combined
|solid |Carbon |Nitrogen| nia |nitrates|nitrogen
|im- | | | | and |
|purity| | | |nitrites|
--------------+------+-------+--------+-----+--------+--------
Rain water | 2·95| ·070 | ·015 | ·029| ·003 | ·042
Upland surface| | | | | |
water | 9·67| ·322 | ·032 | ·002| ·009 | ·042
Deep-well | | | | | |
water | 43·78| ·061 | ·018 | ·012| ·495 | ·522
Spring water | 28·20| ·056 | ·013 | ·001| ·383 | ·396
--------------+------+-------+--------+-----+--------+--------
--------------+---------+--------+-----------------
|Previous | | Hardness
|sewage | +-----+-----+-----
|or animal|Chlorine|Temp-|Perm-|Total
|contamin-| |orary|anent|
| ation | | | |
--------------+---------+--------+-----+-----+-----
Rain water | 42 | ·22 | ·4| ·5 | ·3
Upland surface| | | | |
water | 10 | 1·13 | 1·5| 4·3 | 5·4
Deep-well | | | | |
water | 474 | 5·11 | 15·8| 9·2 |25·
Spring water | 3559 | 2·49 | 11·0| 7·5 |18·5
--------------+---------+--------+-----+-----+-----
RAIN WATER contains, among natural waters, the smallest amount of solid
matter in solution. From the columns headed “Organic Carbon” and “Organic
Nitrogen” it will be seen that even rain collected with special
precautions, away from any large town, is by no means free from organic
matter. Rain water collected from roofs and stored in underground tanks is
often very impure.
SURFACE WATERS form the main supply of rivers. If collected from high
uncultivated districts they are usually unpolluted with animal matter. The
organic matter is usually peaty, is sometimes very small, but is liable to
considerable variations with the season, and is occasionally present in
excessive quantities, discolouring the water and rendering it unpalatable.
From their softness these waters are admirably adapted for manufacturing
purposes. The amount of solid matter in solution ranges from 2 to 7 grains
per gallon.
SURFACE WATER from _cultivated land_, contains on an average less organic
matter than upland surface water, but the pollution, being derived from
manure and other objectionable matter, is more harmful.
RIVER WATER consists of the above, aided by springs, and most frequently
the drainage of towns on its banks. The amount of solid matter varies from
10 to 30 grains per gallon. In Thames water there are on the average about
20 grains.
WELLS, if _shallow_, are usually a most undesirable supply. Unless far
from any house they are contaminated by drainage, and sometimes, from
proximity to cesspools, contain more animal matter than ordinary town
sewage. They are, as a class, hard waters, the polluted ones excessively
so.
Wells of 100 feet deep and upwards are, as a class, very superior waters,
the filtration and oxidation of so great a depth of soil having removed
the greater part of the organic matter. The hardness varies with the
strata, but, as a class, the deep wells are softer than the shallow.
SPRING WATER greatly resembles deep well water, possessing all its good
qualities in a higher degree. Spring and deep well water are very uniform
in quality, and little affected by climatic changes.
SEA WATER. The characteristic of this variety is its saltness. Its density
is about 1·0274, and the average quantity of saline matter which it
contains is about 3-1/2 per cent., of which about 27/35 are chloride of
sodium, and the remainder chiefly chloride of magnesium and sulphate of
magnesium.
The average proportion of organic carbon and nitrogen in 23 samples of sea
water was ·278 carbon, ·165 nitrogen, as compared with Thames water
averages of ·203 parts carbon, ·033 nitrogen, in 100,000 parts of water.
_Analysis of sea water_ (British Channel), by Dr Schweitzer, of
Brighton:——
1000 gr. contained—— Grains
Water 963·745
Chloride of sodium 28·059
Chloride of potassium 0·766
Chloride of magnesium 3·666
Bromide of magnesium 0·029
Sulphate of magnesium 2·296
Sulphate of calcium 1·406
Carbonate of calcium 0·033
————————
1000·
_Pur._ Pure water is perfectly transparent, odourless, and colourless, and
evaporates without residue, or even leaving a stain behind. The purest
natural water is that obtained by melting snow or frozen rain, that has
fallen at some distance from any town. Absolutely pure water can only be
obtained by the union of its gaseous constituents; but water sufficiently
pure for all purposes may be procured by the careful distillation of
common water.
Among the methods adopted for improving the quality of water are:
(_a_) _For reducing the amount of organic and suspended matter._——1.
Filtration through or agitation with coarsely powdered, freshly burnt
charcoal, either animal or vegetable, but preferably the former. When in
good condition a filter of animal charcoal will not only remove suspended
matter in water, but will considerably reduce the amount of organic
matter, and also the calcareous and gaseous impurities held in solution;
but it, however, loses its power of removing lime in a week or two, and of
abstracting the organic matter in about three to four months, and then
becomes foul, and requires to be recharged. Spongy metallic iron is more
energetic in its action than charcoal, and remains serviceable for a
twelvemonth. 2. Free exposure to the action of the air, by which the
organic matters become oxidised and insoluble, and speedily subside. This
may be easily effected by agitating the water in contact with fresh air,
or by forcing air through it by means of bellows. 3. The addition of a
little sulphuric acid has a like effect; 15 or 20 drops are usually
sufficient for a gallon. This addition may be advantageously made to water
intended for filtration through charcoal, by which plan at least 2/3 of
the latter may be saved. (Lowitz.) 4. An ounce of powdered alum
(dissolved), well agitated with a hogshead or more of foul water, will
purify it in the course of a few hours, when the clear portion may be
decanted. When the water is very putrid about 1/2 dr. (or even 1 dr. per
gall.) may be employed; any alum that may be left in solution may be
precipitated by the cautious addition of an equivalent proportion of
carbonate of sodium. 5. A solution of ferric sulphate acts in the same way
as alum; a few drops are sufficient for a gallon. 6. Agitation with about
1/2 to 1 per cent. of finely powdered black oxide of manganese has
similar effect to the last. 7. The addition of a little aqueous chlorine,
or chlorine gas, to foul water, cleanses it immediately. This method has
the advantage of the water being perfectly freed from any excess of the
precipitant by heat.
(_b_) _For reducing amount of inorganic matter._——1. Distillation
separates all non-volatile matter, including organised bodies. It is used
to obtain a potable water from sea water. The waste heat of the cook’s
galley is amply sufficient for this purpose. There are several patent
contrivances for the distillation of water on ship board. 2. Hard water
may be softened by adding carbonate of soda to the water so long as it
turns milky. The precipitation of the hardening ingredients, lime and
magnesia, is most rapid when the water is heated. The water cannot be used
for drinking purposes, from the unpleasant flavour of the carbonate of
soda. When used on a hard water intended for washing, it effects a saving
of soap equal to about fifteen times its own cost. Sea water can be made
fit for washing by this means. It removes both the “temporary” hardness,
due to carbonates of calcium and magnesium, and the “permanent,” due to
the sulphates, chlorides, and nitrates of these metals. 3. Hard water may
be both aerated and softened by the addition of a few grains of
bicarbonate of potassium per gallon, followed by half as much lime juice
or tartaric acid as is sufficient to saturate the alkali in the carbonate
thus added. 4. The “temporary” hardness may be nearly removed by
ebullition, or, as recommended by Professor Clarke, by mixing the hard
water with lime water, when the calcium combines with the excess of
carbonic acid, which previously rendered the carbonate of calcium soluble,
and is precipitated as carbonate (chalk), together with the carbonate
originally present. This method removes, at the same time, much of the
organic matter, and carries down suspended matter. The water is often made
more palatable than before. The directions are:——For every degree of
hardness on Clarke’s scale each 1000 gallons of water to be softened
requires one ounce of quicklime. Slake the lime and work up to a thin
cream with water and pour into the cistern, which already contains at
least 50 gallons of water to be softened. Then add the remainder of the
1000 gallons in such a way as to stir up and mix uniformly with the
contents of the cistern. In about three hours the milky water is clear
enough for washing. After twelve hours’ rest the water is fit to drink. If
the exact hardness of the water is not known, water may be added to the
milk of lime till, on adding a drop of nitrate of silver to a cupful of
the cistern water, the brown tint indicative of an excess of lime is
replaced by a very faint yellow. 5. To save boilers from scaling, water
intended for steam purposes is sometimes treated with lime to remove
carbonates, and then the sulphate of calcium (which forms a very tenacious
scale) is decomposed with baric chloride (Haen’s process). The
precipitated mineral matter may also be prevented from forming a scale or
fur by adding organic substances, such as potatoes, sound or otherwise,
swedes, mangolds, or other vegetable. Oak bark, spent tan, sawdust; and
their decoctions are efficacious on account of the tannic acid they
contain, but they attack the boiler plates at the same time. Zinc
suspended in the water is said to answer well. It has been recommended to
polish the inside of the boiler plates with black lead or coat it with
linseed oil and dissolved india rubber. Numerous chemical preparations,
most of which do more harm than good, are also sold.
_Tests (Physical)._——1. To observe colour, stand in tall colourless glass
cylinder on white ground. If very turbid allow to settle, and examine
sediment by microscope for evidence of sewage contamination (linen fibres,
hairs, epithelium) and for moving organisms. Slight turbidity is best
noted by filling a clean quart flask and holding it towards the light with
some dark object as a window pane between. Taste and odour most marked
when the water is made lukewarm. 2. For poisonous metals add one drop of
strong colourless ammonium sulphide to about 1000 grains of water in glass
cylinder, and observe if liquid darkens. If the coloration or precipitate
disappears on adding acid, it is iron; if it remains, lead or copper is
present, either of which condemns the water. 3. For chlorine add couple of
drops of nitric acid to a little of the water and a crystal or drop of
solution of nitrate of silver. If the water turns very milky it is a bad
sign; make, if possible, a comparative experiment with water of known
composition. 4. The residuum, if any, of evaporation is impurity; if it be
organic matter, smoke and a peculiar odour will be evolved, as the residue
becomes dry and charred. 5. Neither litmus, syrup of violets, nor turmeric
are discoloured or affected when moistened with pure water; if the first
two are reddened it indicates an acid; if the litmus is turned blue or the
turmeric is turned brown, an alkali is present. 6. If a precipitate is
formed or a fur or crust deposited on the vessel during ebullition it
indicates the presence of carbonates of calcium, magnesium, or iron. 7.
Calcium salts produce a white precipitate with oxalate of ammonium. 8. The
liquid filtered off from 7, on standing with phosphate of sodium and
ammonium (microcosmic salt), gives a white precipitate if magnesium be
present. 10. Tincture or infusion of galls turns water containing iron
black. When this takes place both before and after the water has been
boiled, the metal is present under the form of sulphate; but if it only
occurs before boiling, then ferrous carbonate may be suspected, and it
will be precipitated as a reddish powder by exposure to air and heat. 11.
Ferrocyanide of potassium gives a dark blue precipitate in water
containing a ferric salt; and a white one, turning blue by exposure to the
air, in water containing a ferrous salt. 12. If sulphuric acid be run into
water and allowed to cool, and a crystal of sulphate of iron dropped into
the water, a dark brown cloud round the crystal indicates nitrates; the
bleaching of indigo added to the hot mixture of equal parts water and pure
oil of vitriol also indicates the presence of these salts. 13. Sulphuric
acid or sulphates is indicated by a soluble salt of barium throwing down a
white precipitate insoluble in nitric acid.
_Water, Quantitative Analysis of._——The quantitative analysis of potable
water is confined to the following: total residue, hardness temporary and
permanent, chlorine, ammonia, nitrates and nitrites, and organic matter.
Of these, all but the first two are intended to throw light on the organic
contamination of the water. Chlorine, ammonia, and nitrates and nitrites
are in themselves innocuous substances, but are estimated because they
supplement the somewhat imperfect information obtained from the organic
matter itself. A sewage-polluted supply being an agent in propagating
zymotic diseases, a knowledge of the source of the organic matter in a
water is of the highest importance.
Before passing to the mode of estimating the above items it may be
desirable to explain the object of each analysis and the interpretation
which may be placed on the results.
_Total solid residue_ includes all the substance, organic or mineral,
dissolved in the water. Everything beyond the two gases which enter into
the combination of the water being useless, the ‘residue’ of a water is
sometimes called the ‘total solid impurity.’ The less residue left by a
water on evaporation the better, but a water need not be objected to for
drinking purposes till the residue reaches 40 grains per gallon. For
raising steam a water should not contain more than 20 grains, and should
be, if possible, much less.