3. COFFEE, BEET-ROOT. From the yellow beet-root, sliced, dried in a kiln
or oven, and ground with a little coffee.
4. COFFEE, DANDELION. From dandelion roots, sliced, dried, roasted, and
ground with a little caramel.
5. COFFEE, GERMAN. _Syn._ SUCCORY C., CHICORY C. From chicory or succory.
Used both for foreign coffee, and to adulterate it.
_Obs._ All the above are roasted, before grinding them, with a little fat
or lard. Those which are larger than coffee-berries are cut into small
slices before being roasted. They possess none of the exhilarating
properties or medicinal virtues of foreign coffee.
COINS. See MEDALS and ELECTROTYPE.
=COKE.= Charred or carbonised coal. The principle of its manufacture is
similar to that of charcoal. There are three varieties of coke:--
1. KILN-MADE COKE; STIFLED COKE. Made by burning pit-coal in a pile, kiln,
or stove. It has a dull-black colour, and produces an intense heat when
used as fuel. By condensing the bituminous vapours which are given off
during the process, about 3% of tar may be obtained from common coal, and
from some strong coal, by careful treatment fully 10% of its weight. The
screenings of dust coal, separated from the better kinds of bituminous
coal, is the sort commonly used for making coke in ovens.
2. GAS COKE; DISTILLED COKE. The cinder left in the gas retorts. Grey;
produces a weak heat, insufficient to smelt iron.
3. SHALE COKE; MINERAL CARBON. From bituminous shale, burnt in covered
iron pots, in a similar way to that adopted for making bone-black; or in
piles. Black and friable. Used to clarify liquids, but is vastly inferior
to bone-black, and does not abstract the lime from syrups. See FUEL,
PIT-COAL, &c.
=COLCHICIN'A.= _Syn._ COL'CHICINE. COLCHICIA. A peculiar principle
discovered by Gieger and Hesse in the seeds of the _Colchicum autumnale_
or common meadow saffron. It also exists in the corms or bulbs.
_Prep._ Macerate the bruised seeds in boiling alcohol, add magnesia, to
throw down the alkaloid, digest the precipitate in boiling alcohol, and
filter. By cautious evaporation colchicine will be deposited, and maybe
purified by re-solution and crystallisation in alcohol.
_Prop., &c._ Odourless; bitter; soluble in water and alcohol; form salts
with the acids. It is very poisonous. 1/10th of a grain, dissolved in
spirit, killed a cat in 12 hours. It differs from veratria in being
soluble in water and crystalline, and in the non-production of sneezing
when cautiously applied to the nose. Strong oil of vitriol turns this
alkaloid of a yellowish-brown; nitric acid turns it of a deep violet,
passing into indigo-blue, green and yellow. It is not used in medicine.
=COL'CHICUM.= _Syn._ MEA'DOW SAF'FRON; COLCHICUM AUTUMNALE (Linn.), L. The
recent and dried corms or bulbs (_colchici cormus_), as well as the seeds
(_colchici semina_), are official in the British Pharmacop[oe]ia. The
corms are ordered to be dug up in the month of July, or before the
autumnal bud has projected. The dry coatings having been torn off, cut the
corms transversely in thin slices, and dry, at first with a gentle heat,
but afterwards slowly increased to 150° Fahr.
_Dose_ (of the corms), 2 to 8 or 9 gr.; (of the seeds), 2 to 7 gr., made
into a pill or bolus with syrup or conserve; chiefly, as a specific in
gout, to alleviate or check the paroxysm. This drug forms the base of
almost all the advertised gout nostrums. It is, however, an active poison,
and its administration requires care. "After all that has been said
respecting colchicum in gout, and admitting that it rarely fails to allay
pain and check a paroxysm, I would record my opinion that he who would
wish to arrive at a good old age should eschew it as an _ordinary_ remedy,
and consider that he is drawing on his constitution for a temporary
relief, with a certainty of becoming prematurely bankrupt in his vital
energies." (Collier.)
_Antidotes._ An emetic consisting of one scruple of sulphate of zinc
dissolved in water, followed by a brisk dose of castor oil, then
stimulants, and also charcoal.
=COL'COTHAR.= See OXIDES OF IRON.
=COLD.= _Syn._ FRI'GUS, L. The privation of heat. The term is also applied
to the sensation and effects which this privation produces.
When the body of an animal is immersed in an atmosphere at a temperature
below the healthy standard, a sensation of coldness is experienced,
produced by the passage of the caloric or heat of the body into the colder
medium. If this extraction of caloric exceeds the quantity produced by the
vital system, the temperature of the body decreases, until it sinks below
the point at which the functions of life can be performed. This
declination of the heat of the body is gradual; the extreme sensation of
coldness changes into a disinclination for voluntary motion; next comes on
drowsiness, followed by numbness and insensibility. At this point if the
sufferer is not rescued, and remedial measures had recourse to, death
inevitably and rapidly ensues.
The prevention of the effects of cold consists in the use of ample food
and clothing proportioned to the inclemency of the weather, the exposure
to be endured, and the habits of the wearer. The circulation of the blood
should be promoted by active exercise, and any disposition to sleep shaken
off by increased bodily exertion. The principal endeavour should be to
keep the extremities and chest warm, as, if this can be accomplished, no
danger need be feared.
In cases of asphyxia produced by intense cold, the patient should be laid
in a room remote from the fire, and bathed with cold salt-and-water, or
water to which some brandy or vinegar has been added; after which the body
should be wiped dry, and friction assiduously applied by the hands of the
attendants (warmed); as many operating at once as can conveniently do so.
Gentle stimulants should be administered by the mouth, and the bowels
excited by some mild, stimulating clyster. The lungs should also be
inflated, and an effort made to re-establish the respiration. As soon as
symptoms of returning animation are evinced, and the breathing and
circulation restored, the patient should be laid in a bed between
blankets, and a little wine-and-water administered, and perspiration
promoted by heaping an ample quantity of clothing on the bed. Should the
patient have suffered from hunger as well as cold, the appetite may be
appeased by the administration of a limited quantity of light food, taking
especial care to avoid excess, or anything indigestible or exciting, &c.
See ASPHYXIA, BRONCHITIS, CATARRH, &c.
=COLD CREAM.= A snow-white, bland ointment, about the consistence of good
lard, and an admirable substitute for that excipient where expense is no
object, especially for applications about the face. It is commonly sold as
a lip-salve and as a healing application to abraded and chapped surfaces
generally. The ordinary receipts are given under the head of COSMETIC
CERATE (which _see_). The following produces a superior article.
_Prep._ (Dr L. Turnbull.) From white wax, 1 oz.; oil of almonds, 4 oz.;
rose-water, 2 oz.; borax, 1/2 dr.; oil of roses, 5 drops. Melt, and
dissolve the wax in the oil of almonds by a gentle heat; dissolve the
borax in the rose-water, which is then to be warmed a little and added to
the heated oil; lastly, add the oil of roses, stirred.
=COL'IC.= _Syn._ COL'ICA, L. The belly-ache or gripes. The name is
popularly given to all severe griping abdominal pains, without reference
to the cause. There are several varieties of this disease, as noticed
below.
=Colic, Accident'al.= Produced by improper food, and poisons. The
treatment may be similar to that recommended for bilious or flatulent
colic.
=Colic, Bil'ious.= In this variety the pain is intermittent and transient,
accompanied by constipation, nausea, and vomiting. The fæces, if any, are
bilious, dark-coloured, and offensive. The common remedies are, a full
dose of blue pill, calomel, colocynth, or aloes, followed by a sufficient
quantity of Epsom salts or Glauber's salts. Warm fomentations are also
serviceable.
=Colic, Flat'ulent.= Marked by constipation, and the irregular distension
of the bowels by gas, accompanied by a rumbling noise, &c. It is commonly
produced by the use of indigestible vegetables and slops. The remedies
are, a full dose of tincture of rhubarb combined with a few drops of
essence of peppermint. If this does not afford relief, an Abernethy pill
may be taken, washed down with a glass of any cordial water, as
peppermint, cinnamon, or caraway. When the pain is extreme, warm
fomentations to the belly, or a carminative clyster, will generally give
relief. The Editor has found castor oil and Collis Browne's chlorodyne of
great benefit in this complaint.
=Colic, Paint'er's.= _Syn._ PLUMB'ER'S COLIC, DEVONSHIRE C., LEAD C.;
COL'ICA PICTO'NUM, L. The dry belly-ache. It is marked by obstinate
costiveness, acrid bilious vomitings, violent pains about the region of
the navel, convulsive spasms in the intestines, and a tendency to
paralysis in the extremities. It is most prevalent in the cider counties,
and amongst persons exposed to the fumes of lead. The remedies are the
same as for the spasmodic variety. Should these fail, after the bowels
have been thoroughly evacuated, small doses of camphor and opium may be
administered, and sulphuric beer or sweetened water very slightly
acidulated with sulphuric acid, had recourse to as a beverage. Mr Benson,
the managing director of the British White-lead Works at Birmingham,
says:--"Although during several weeks after the addition of the sulphuric
acid to the treacle beer, drank at the works, little advantage seemed to
be derived, yet the cases of lead colic became gradually less frequent,
and since October of that year, or during a period of fifteen months, not
a single case of lead colic has occurred amongst the people." ('Lancet.')
See BEER, SULPHURIC ACID, and SULPHURIC ACID.
=Colic, Spasmod'ic.= Marked by a fluctuating pain about the navel, which
goes away and returns by starts, often leaving the patient for some time.
The belly is usually soft, and the intestines may often be felt in lumps,
which move about under the hand, or are wholly absent for a time. It is
unaccompanied by flatulency. The remedies are warm fomentations, warm
clysters, and carminatives, accompanied by small doses of camphor and
opium.
=Colic, Stercora'ceous.= Marked by severe griping pains and constipation
of the bowels. The remedies are powerful cathartics, as full doses of
calomel, aloes, colocynth, jalap, &c., followed by purgative salts, as
sulphate of magnesia, or sulphate of soda.
=Colic in Horses.= First give the horse a sharp trot, and apply friction
over the belly, and follow this up with a drench of warm gruel to which
has been added a glass or two of whisky or gin. Should these fail to give
relief, let 4 dr. of aloes be rubbed down in a pint of hot water, and when
the mixture becomes cool enough, add from thirty to sixty drops of strong
solution of ammonia. Where the spasms and distress continue severe, and
with little intermission, the physic may be followed in an hour with 2 dr.
of tincture of aconite, given with an ounce of spirit of chloroform, in a
little water, and repeated every hour; soap and water clysters should be
administered every half hour, and friction and hot fomentations applied to
the abdomen.
=COLLO'DION.= _Syn._ COLLO'DIUM, L., B. P. A viscid fluid formed by
dissolving pyroxylin (Schönbein's gun-cotton) in a mixture of ether and
alcohol. In _surgery_ it is used in its natural state, and combined with
certain elastic and medicinal substances. In _photography_ it is used in
combination with agents that render it sensitive to the action of light.
=Collodion.= _Syn._ PLAIN COLLODION. The following are the best methods of
preparing plain collodion for surgical purposes:--
_Prep._ 1. (Ph. U. S.) Nitrate of potassa, in powder, 10 oz.; sulphuric
acid, 8-1/2 fl. oz.; triturate together in a wedgwood mortar until
uniformly mixed; then add of fine carded cotton (free from impurities),
1/2 oz.; and by means of the pestle or a glass rod, saturate it thoroughly
with the liquor for a period of about 3 or 4 minutes; next transfer the
cotton to a vessel containing water, and wash it in successive portions of
pure water, with agitation and pressure, until the washings cease to
affect litmus paper or a solution of chloride of barium; it is then to be
spread out and dried by a very gentle heat, and dissolved by agitation in
a stoppered bottle with rectified sulphuric ether, 1 quart, to which
rectified spirit (alcohol), 1 fl. oz., has been previously added.
2. (Mialhe.) Nitrate of potassa, 40 parts; concentrated sulphuric acid, 60
parts; carded cotton, 2 parts; proceed as last until the dry cotton is
obtained, then take of the prepared cotton, 8 parts; rectified sulphuric
ether, 125 parts; mix in a well-stoppered bottle, and agitate it for some
minutes; then add gradually, rectified alcohol, 1 part; and continue to
shake until the whole of the liquid acquires a syrupy consistency. It may
be now passed through a cloth; but a better way to prevent loss is to let
it repose for a few days, and then decant the clear portion.
3. (Lauras.) This process only differs from No. 2 in the following
particulars:--The cotton is immersed for 12 minutes, then rinsed 2 or 3
times in cold water, and afterwards immersed in a solution of carbonate of
potassa, 4 parts, and water, 200 parts. Lastly, it is plunged again into
simple water, and dried at a temperature of 77° to 86° Fahr.
4. (B. P.) Pyroxylin, 1 part; rectified spirit, 12 parts; ether, 36 parts;
mix the ether and spirit, and add the pyroxylin. Keep in a well-corked
bottle.
5. (Parrish.) Thoroughly saturate clean carded cotton, 1/2 oz., with
fuming nitric acid and sulphuric acid, of each 4 fl. oz., previously mixed
and allowed to become cool; macerate for 12 hours; wash the cotton in a
large quantity of water; then free it from the water by successive
washings in alcohol, and dissolve in ether, 3 pints.
_Obs._ For success in the manufacture of collodion it is absolutely
necessary to avoid the presence of water. The ordinary commercial oil of
vitriol, sp. gr. 1·84, may be used. Professor Procter, of Philadelphia,
gives preference to the process with the mixed acids (No. 5), and directs
that the cotton should be allowed to macerate for four days. In drying the
cotton great care should be taken to prevent an explosion.
_Uses, &c._ In _surgery_ plain collodion is employed as a dressing for
wounds, and as a protection to abraded surfaces. On drying, it unites the
former closely, and preserves the latter from the action of the air. It is
impervious to water, and being transparent, it admits of the progress of
the wound being inspected when necessary. Such is its adhesive power, that
a piece of cloth cemented with it to the dry palm of the hand will support
a weight of 25 to 30 lbs. The parts to which it is applied should be freed
from moisture. See COLLODIONS, COLOURED, ELASTIC, MEDICATED and VESICATING
(_below_).
=Collodion, Blis'tering.= See VESICATING COLLODION.
=Collodion, Col'oured.= _Syn._ COLLODIUM TINCTUM, L. _Prep._ (Cutan.
Hosp.) Collodion, 2 oz.; palm oil, 1 dr.; alkanet root, q. s. to colour
(say 15 gr.); digest and decant the clear. Colour bears a greater
resemblance to the skin than that of common collodion, whilst it is more
flexible; but it is weaker than the latter.
=Collodion, Elas'tic.= _Prep._ 1. (Lauras.) Heat together Venice
turpentine, 2 parts; castor oil, 2 parts; and white wax, 2 parts; add
sulphuric ether, 6 parts; and mix all with the product of No. 3 (_above_),
that is, to the collodion formed with 8 parts of prepared cotton, 125
ether, and 8 alcohol.
2. (C. S. Rand.) Dissolve prepared cotton (No. 5, _above_), 2 dr., in
sulphuric ether, 5 fl. oz.; then add, Venice turpentine, 2 dr., and
complete the solution by slight agitation.
_Obs._ The collodion made by either of the above processes, when applied
to the skin, forms a transparent pellicle, more pliable and more difficult
to remove than that of ordinary collodion.
=Collodion, Flexible.= COLLODION FLEXILE. (B. P.) Mix collodion (B. P.), 6
fl. oz., with Canada balsam, 120 gr.; and castor oil, 1 fl. dr., and keep
in a well-corked bottle.
=Collodion, Hemostatic.= Collodion, 10 parts; carbolic acid, 1 part;
tannic acid, 1/2 part; benzoic acid, 1/2 part; all by weight. To be
applied with a pencil brush.
=Collodion, Iodised.= This may be made at one operation; it should be kept
two days before being used, but is less reliable if kept for any length of
time than the sensitised collodion described below. It is made as
follows:--Place 16 grains of gun-cotton in a bottle, add 18 grains of
iodide of cadmium in powder, 6 grains of bromide of cadmium in powder, and
1-1/2 oz. of spirits of wine (sp. gr. 0·805). Shake the bottle until the
iodide and bromide are dissolved, then add 3 oz. of ether, sp. gr. 0·720,
and shake until the cotton is dissolved. After settling for twenty-four
hours, decant the clear portion into small well-stoppered bottles.
=Collodion, Med'icated.= It has been proposed to medicate collodion in
several ways, but the practice has not found much favour with the medical
profession. The following preparations have been described:--
COLLODION, ACONITE. From aconite root, by a similar formula to that of
BELLADONNA C. (_below_).
COLLODION, BELLADONNA. _Prep._ Macerate select belladonna leaves,
powdered, 8 oz., in ether, 12 fl. oz., with alcohol (95%), 4 fl. oz., for
six hours. Pack in a percolator, and pour en alcohol till a pint of
tincture is obtained; in this dissolve pyroxylin (gun-cotton), 1 dr., and
Canada balsam, 1/2 oz. Used as a substitute for BELLADONNA PLASTER.
COLLODION, CANTHARIDIN. See COLLODION, VESICATING.
COLLODION, IODINE. _Prep._ Dissolve iodine and Canada balsam, of each 1/2
oz., in collodion, 1 pint. Used as a substitute for IODINE OINTMENT.
=Collodion, Morphia.= (L'Union Medicale.) Dissolve 1 part of hydrochlorate
of morphia in 30 parts of flexible collodion, and apply with a camel-hair
brush.
=Collodion, Photograph'ic.= 1. There are so many methods adopted for
preparing photographic collodion, that a large volume might be filled with
notices of them. We have retained Mr Hardwich's forms, which were formerly
much esteemed by practical photographers, and appended to them modern
formulæ which are now, we believe, in much greater demand, and for which
we are indebted to Mr Ernest Spon's valuable book 'Workshop Receipts.'
2. Pyroxylin, and iodide of cadmium, or ammonium, of each 15 gr.; ether,
3-1/2 oz.; alcohol, 1-1/2 oz. Place the two first in a dry bottle, then
pour on the spirits of wine, shake the mixture well, then add the ether,
shake again and let it stand for 12 hours. Decant the clear portion into a
wide-mouthed bottle, keep well stoppered, and in the dark. Avoid shaking
the bottle when about to use the collodion, and never quite use all the
bottle contains, as the sediment which will accumulate at the bottom would
spoil the picture. The preparation of a sensitive collodion, whether
positive or negative, includes three distinct operations, namely, the
formation of the pyroxylin or gun-cotton, the conversion of this into
plain collodion, and the final process of iodising the collodion.
=Collodion, Plain.= Mix in a bottle gun-cotton, 450 gr.; ether, 25 oz.;
spirits of wine, 7 oz. Shake these well together, and leave to settle
several days. Keep well corked.
=Collodion, Pos'itive.= (Hardwich.) To form the PYROXYLIN:--Take sulphuric
acid, sp. gr. 1·845, at 60° Fahr., 12 fl. oz.; nitric acid, sp. gr. 1·45,
at 60°, 12 fl. oz.; water, 3-1/2 fl. oz.; mix, and allow the temperature
to fall to 140°; then immerse cotton, 300 grains. (If the cotton is found
to gelatinise or dissolve in the acid mixture, the quantity of water is
too great, and may be reduced to 3 fl. oz.) The cotton should be well
pulled out in pieces, weighing about 30 grains each; and should be left in
the acid for about 8 minutes, the vessel being covered over. It is taken
out with a glass spatula, squeezed to remove acid, washed for at least 24
hours by a stream of water, then squeezed in a cloth, and pulled out to
dry. To form the PLAIN COLLODION:--Shake up the dry pyroxylin, 48 grains,
with alcohol, sp. gr. ·805, 1-1/2 fl. oz., and then add ether, sp. gr.
·725, 4-1/2 fl. oz. The solution should be allowed to rest for a week or
ten days, when the clear fluid should be decanted from the sediment. To
prepare the IODISING SOLUTION:--Take of iodide of ammonium, 1-1/2 dr.;
iodide of cadmium, 1-1/2 dr.; bromide of ammonium, 40 grains; powder, and
dissolve in alcohol, sp. gr. ·805 to ·816, 10 fl. oz. The collodion is
iodised by adding the solution to it in the proportion of 1 part solution
to 3 parts collodion. The iodised collodion should be kept for at least
six weeks before using. If required for immediate use, add a few drops of
an alcoholic solution of iodine, formed by dissolving 5 grains of iodine
in 1 fl. oz. of alcohol.
_Obs._ Mr Hardwich recommends that the cotton, before being converted into
pyroxylin, should be cleansed by boiling for two hours in a solution of
caustic potassa (2 oz. to the gallon), and by being afterwards repeatedly
washed and dried. The purest nitric acid, sp. gr. 1·45, should be
employed, but the ordinary commercial sulphuric acid (oil of vitriol) is
sufficiently pure for use. To purify the ETHER and to get rid of a certain
ozonised principle which would decompose the iodising solution, Mr
Hardwich recommends the following process:--Take the best washed ether of
commerce and agitate it thoroughly with a small portion of dilute
sulphuric acid, and then introduce it into a retort, and distil over one
third. The alcohol used is of the strength of that sold for absolute
alcohol; it should be pure.
=Collodion, Neg'ative.= (Hardwich.) To form the PYROXYLIN:--Take of
sulphuric acid, sp. gr. 1·845, at 60°, 18 fl. oz.; nitric acid, sp. gr.
1·475, at 60°, 6 fl. oz.; water, 5-1/4 fl. oz.; cotton, 300 grains. Mix,
and allow the temperature to fall to 150° Fahr. The weight of the
pyroxylin ought to be 375 grains. To form the PLAIN COLLODION:--Take
alcohol, sp. gr. ·806, 1/2 gallon; ether, sp. gr. ·725, 1 gall.;
pyroxylin, 1900 grains. Saturate the pyroxylin with the alcohol, then pour
in half a gallon of the ether, agitate for 3 or 4 minutes, and repeat the
process in adding the remainder. Decant the clear liquid from the sediment
after a week or ten days' rest. The following forms for IODISING SOLUTIONS
are recommended:--_a._ (Potassium Iodiser.) Iodide of potassium, 135
grains; alcohol, sp. gr. ·816, 10 fl. oz. Powder and dissolve in the
alcohol, previously heated to 140°.--_b._ (Cadmium Iodiser.) Iodide of
cadmium, 170 grains; alcohol, sp. gr. ·816, 10 fl. oz. Dissolve in the
cold, and filter.--_c._ (Bromo-iodiser.) Bromide of ammonium, 40 grains;
iodide of ammonium, 90 grains; iodide of cadmium, 90 grains; alcohol, sp.
gr. ·816, 10 fl. oz. Pulverise and dissolve in the cold. To sensitise the
collodion, add to three parts one part of either _a_, _b_, or _c_.
_Obs._ Most of the practical directions given under the head of POSITIVE
COLLODION apply equally to NEGATIVE COLLODION. Nothing but patient and
intelligent practice will ever lead to success in preparing collodion for
photographic purposes. Although formulæ of undoubted excellence may be
used, it continually happens that the results are entirely nugatory from
some trifling cause. See PHOTOGRAPHY.
=Collodion, Sensitised.= Add to 1 oz. of the plain collodion 6 drams of
spirits of wine; 1-3/4 oz. of ether; and 3 drams of iodide and bromide
solution (see _below_). Shake the bottle well; the mixture is then ready,
but is improved by being kept four or five hours before using. In hot
weather a little more alcohol and less ether; in very cold weather more
ether and less alcohol must be used. As sensitised collodion does not keep
well, it is better not to mix the plain collodion and the iodide and
bromide solution until shortly before required for use.
=Iodide and Bromide Solution.= Iodide of cadmium 154 grains; bromide of
cadmium 54 grains; spirits of wine, 3-1/2 ounces. Pound the iodide and
bromide very fine in a mortar, adding the spirit gradually; when the
iodide and bromide are dissolved, pass the solution through a filter paper
into a bottle. Must be kept in a closely-stoppered bottle.
=Collodion, Styptic.= _Syn._ STYPTIC COLLOID. (Dr Richardson.) To a
saturated solution of tannic acid in alcohol and ether, in equal parts,
add as much pyroxylin as the liquid will dissolve.
=Collodion, Ves'icating.= _Syn._ BLIS'TERING COLLODION, CANTHAR'IDIN C.;
COLLO'DIUM VES'ICANS, L. _Prep._ 1. (Tichborne.) Coarsely powdered
cantharides, 6 oz., are placed loosely in a displacement apparatus
(provided with a tap to regulate the flow), and treated with ether from
methylated spirit, 13 fl. oz., and glacial acetic acid, 2 fl. oz.,
previously mixed together. After the fluid has passed through, it will be
found that the _débris_ has retained by absorption 7 fl. oz., which must
be displaced by the gradual addition of methylated spirits of wine, 7 fl.
oz. If properly managed, there is not the least danger of the admixture of
the spirits with the percolated menstruum, as the animal substance of the
flies swells considerably under the prolonged influence of the spirits of
wine, so that the same bulk will be insufficient to quite displace the
ether. The ethereal solution should be made to measure exactly 15 fl. oz.
with a little spirit, and may then be converted into a collodion by the
addition of pyroxylin, 1/2 oz.
_Obs._ The glacial acid plays a double part in this preparation. It
dissolves the cantharidin, and at the same time gives to the collodion
film the essential property of porosity. Ordinary collodion is useless as
an excipient, for it produces a tough and contractile film, which really
screens the skin from the action of the greater part of the blistering
material.
2. (Ilisch.) Cantharidin, 15 gr.; pyroxylin, 20 gr.; rectified ether,
1-1/2 oz.; acetic ether, 1/2 oz.; dissolve.