That of Valentia (Ireland) taken as 1 or 100.
Ireland, Valentia ·1
Scotland, sea-coast, country places, west 2·69
Scotland, inland, country places, west 2·96
Scotland, sea-coast, country places, average 4·10
Scotland, sea-coast, country places, east 5·51
England, inland, country places, east 5·94
England, sea-coast, country places, west 10·55
German specimens 10·61
London, 1869 19·17
Scotland, towns (Glasgow not included) 21·22
St. Helen's 25·33
Runcorn 25·72
England, towns 28·67
Liverpool 29·89
Manchester, 1869 35·33
Manchester, 1869 and 1870, average 35·94
Manchester, 1870 36·54
Glasgow 50·55
The effects resulting from breathing an impure atmosphere are necessarily
dependent upon the extent of the pollution and other conditions. When the
contamination is moderate the first effect is headache, accompanied with
lassitude, and a general paleness of the face and skin, owing to a
diminution of the red corpuscles of the blood or to their imperfect
aëration; the pulse becomes lowered, and at the same time the breathing is
accelerated. When in addition to breathing such air from day to day is
superadded the misfortune of an insufficiency of food, scrofula and
consumption very often follow. Dr Guy has demonstrated the great mortality
that is caused by consumption in those trades in which workmen pursue
their calling in hot, close, gas-lit rooms, in comparison with those who
pass most of their time in the open air. The amount of air required by
each person in a room is no less than 2100 feet per hour; when the
ventilation does not supply this amount of fresh air, the apartment smells
stuffy, the furniture becomes coated with a film of organic matter, unless
constantly cleaned, and the carbonic acid becomes increased beyond its
normal quantity.
Dr Parkes has shown that bronchitis and consumption are more frequently
than not contracted by those who live in an atmosphere of foul air. In the
years 1834 to 1847 the proportion of deaths in the ill-ventilated prison
of Leopoldstadt in Vienna was 86 per 1000, out of which number 51·4 per
1000 was due to phthisis or consumption; while in the well-ventilated
House of Correction in the same city the deaths were 14 per 1000, of which
7·9 were from phthisis; hence 43·5 cases per 1000 of the deaths were
clearly traceable to foul air and nothing else.
Mr Noel Hartley, in his valuable little manual, 'Water, Air, and
Disinfectants,' says: "During the outbreak of cattle plague in 1866, in
sheds containing twenty to thirty cows--which the owners kept closed to
such an extent that all chinks in the doors and windows were stuffed with
straw and matting, under an ignorant belief that thus the plague could be
kept out--very frequently the entire stock died in two or three days after
the first appearance of disease; while in other cases where animals were
housed in a well-cleaned and tidily-kept shed, with a plentiful supply of
fresh air, not only did some of them escape the disease altogether, but
the deaths were reduced to one third of the number of beasts attacked."
The large supply of fresh air necessary in hospitals for contagious
diseases is fully recognised by medical men, and more especially so in
America. Wounds carefully protected from contact with impure air do not
suppurate, and organic fluids do not putrefy. On the other hand, in a bad
atmosphere sores become unhealthy, and are difficult to heal, erysipelas
and hospital gangrene frequently set in, while the best prevention and the
best means of cure for such afflictions is the greatest possible exposure
to fresh air.
Vitiated air, as a consequence of over-crowding, aids the spread of
measles, scarlet fever, and the much to be dreaded smallpox; it brings on
ophthalmia, a troublesome inflammation of the eyes, and is not
unfrequently the cause of the ricketty and scrofulous condition of
children. Although exposure to cold does cause such affections as
bronchitis, pneumonia, cold in the head, sore throat, and other affections
of the respiratory organs, it is more frequently the case that they are
the result of a sudden change of temperature, such as experienced in
coming out of a crowded assembly in a close, badly-ventilated building,
than by actually cold weather. This is decidedly and strikingly shown by
the fact which Dr de Chaumont has quoted, that the British Army when in
the Crimea, when lodged in tents during extremely rigorous weather,
experienced a wonderful condition of health, such a thing as a cold being
an unknown complaint; but when some of the men were placed in huts which
were much warmer, and into which there was a smaller circulation of fresh
air, the sick rate increased, and coughs and colds began to put in an
appearance. Persons who during summer and winter sleep with their windows
more or less open cannot endure a night spent in the chamber with the
chimney closed and the window shut. A less refreshing sleep occupies the
night, and a somewhat feverish sensation is felt next morning.
If in cold weather the window be opened only one inch at the top, the
difference in the air in the bedroom is something quite beyond
comprehension to those who have not paid attention to these things. See
VENTILATION.
=Air, Analysis of.= Priestley's discovery of oxygen gas in 1774 prepared
the way for the knowledge of the real composition of air, which was
discovered about the same time by Scheele and Lavoisier. Scheele's method
of operating was by exposing some atmospheric air to a solution of
sulphide of potassium. Lavoisier effected the same object by the
combustion of iron wire and phosphorus, and subsequently by heating
mercury on a flask filled with air for some time, just below its boiling
point.
These, however, were but elementary methods, which, however creditable to
the ingenuity of the great founders of modern chemistry, not only failed
in accuracy, but took no account of the presence and amount of two most
important constituents in the atmosphere, viz. carbonic anhydride (acid)
and ammonia.
_Determination of Aqueous Vapour._ To effect this an aspirator must be
used (see ASPIRATOR). This instrument is easily made, and is not
expensive. The accompanying figure will illustrate the arrangement
generally adopted: _a_ is an aspirator made of galvanised iron or sheet
zinc. It holds from 50 to 200 litres (from 11 to 44 gallons). By this
means a known volume of air is drawn through the tubes marked _b_, _c_,
_d_, _e_, which may be filled with pumice-stone moistened with strong
sulphuric acid; but if the carbonic acid is to be estimated as well, _b_
and _c_ are filled with moist hydrate of lime (potash used to be employed,
but hydrate of lime is to be preferred, as the potash absorbs oxygen), and
_d_ and _e_ as above. Each of the tubes is accurately weighed previously
to connecting them with the apparatus.
[Illustration]
It is imperative to have each of the tubes connected by perfectly
air-tight joints. The gain of weight in _d_ and _e_ gives the water in _b_
and _c_ the carbonic acid.
_Determination of Carbonic Acid._ A better and perhaps more exact means of
determining the carbonic acid is that invented by PETTENKOFER. It may be
briefly described as follows:--Baryta water of definite strength is
prepared and accurately standardised by a standard solution of oxalic
acid. A portion of this baryta water is then made to act upon a definite
quantity of air. It will absorb the whole of the carbonic acid in that
air.
The alkalinity of the liquid will in consequence be diminished; it will
take less of the oxalic-acid solution than before, which shows so much
less caustic baryta, and from which the carbonic acid absorbed may be
easily calculated.
_The actual Analysis._ Two kinds of baryta water may be used, the one
containing 7 grammes to the litre, the other three times that strength; 1
c. c. of the stronger = 3 m. grms. of carbonic acid; 1 c. c. of the weaker
= 1 m. grm. The baryta water is best kept in the bottle represented below.
[Illustration]
The bottle (_a_) contains the baryta water. It has an accurately-fitting
double-perforated stoppered caoutchouc. The left-hand tube is connected
with the tube (_b_) containing pumice-stone moistened with potash, while
the right-hand one is a syphon. When required for use the stop-cock (_f_)
is opened, and suction applied by a glass tube to F. The syphon is thus
filled and the stop-cock closed. If a pipette is required to be filled its
nozzle is inserted at F, the stop-cock compressed, and the fluid
immediately rises into the pipette.
The air entering the bottle as the fluid decreases in _a_ is, of course,
thoroughly deprived of its carbonic acid by the tubes at _b_.
The first thing to be done is to standardise the baryta solution by a
solution of oxalic acid, containing 2·8636 grammes of crystallised oxalic
acid to the litre.
Thirty c. c. of baryta solution are run into a small flask, and the oxalic
acid run in from a Mohr's burette with float, the vanishing-point of the
alkaline reaction being ascertained by delicate turmeric paper. As soon as
a drop placed on turmeric paper does not give a brown ring the end is
attained.
The actual analysis is performed by filling a bottle of known capacity,
with the aid of a pair of bellows, with the air to be analysed, then
distributing over its sides 45 c. c. of the baryta water it is left for
half an hour. The turbid water is poured into a cylinder, closely secured,
and allowed to deposit; then take out 30 c. c. by a pipette of the clear
fluid, run in the solution of oxalic acid, multiply the volume used by
1·5, and deduct the produce from the c. c. of oxalic acid used for 45 c.
c. of the fresh baryta water. A different method has been suggested by Dr
Angus Smith, viz. to measure the carbonic anhydride by the turbidities of
the baryta water; this is, in fact, a colorimetric test. For rough
approximative results Dr Smith's process will be found a very useful and
convenient one. It depends upon the fact that the amount of carbonic acid
in a given quantity of air will not produce a precipitate in a given
quantity of lime or baryta water unless the carbonic acid is in excess.
The following is one of his tables:--Columns 1 and 2 give the rates of
carbonic acid in the quantity of air which will produce no precipitate in
half an ounce of lime water. Column 3 is the same as column 2; but 14·16
c. c. (half an ounce) is added to give the corresponding size of the
bottle, and column 4 gives the size of the bottle in ounces.
To be used when the point of observation is "no
precipitate." Half an ounce of baryta water contains
about ·08 gramme of baryta.
Air at 0° C. and 760 millims. Bar.
Carbonic Acid Volume of Size of bottle Size of bottle
in the Air, Air in cubic in cubic in ounces
per cent. centimètres. centimètres. Avoirdupois.
·03 185 199 7·06
·04 139 154 5·42
·05 111 125 4·44
·06 93 107 3·78
·07 79 93 3·31
·08 70 84 2·96
·09 62 76 2·69
·10 56 70 2·46
·11 51 65 2·29
·12 46 60 2·14
·13 43 57 2·01
·14 40 54 1·90
·15 37 51 1·81
·20 28 42 1·48
·25 22 36 1·29
·30 19 33 1·16
·40 14 28 1·04
·50 11 25 ·89
·60 9 23 ·89
·70 8 22 ·78
·80 6 20 ·72
1·00 5·5 19·7 ·70
Mr Wanklyn's process for the determination of carbonic acid in the
atmosphere is as follows:--A solution of carbonate of soda is first made
as follows: 4·47 grammes of gently-ignited carbonate of soda are dissolved
in one litre of water, giving a solution of such a strength that 1 c. c.
contains exactly 1 c. c. of carbonic acid (= 1·97 milligrammes of CO_{2});
a large quantity of baryta water (strength about 0·1 per cent.) is
prepared.
If now 100 c. c. of clear baryta water be treated with 1 c. c. of
carbonate of soda, just described, a certain degree of turbidity is
produced.
If 2 c. c. of the solution be taken another degree of turbidity is
produced, and so on. If, then, a bottle capable of holding 2000 c. c. of
air, together with 100 c. c. of baryta water, be filled with the sample of
air to be tested, there will be a certain depth of turbidity produced by
shaking it up. Having got the air to expend itself on 100 c. c. of baryta
water the degree is to be found by comparison with another 100 c. c. of
baryta water, in which a like turbidity has been induced by means of the
standard solution of carbonate.
Every c. c. of soda solution counts for a c. c. of carbonic acid in two
litres of air. A consumption of 1 c. c. will correspond to ·05 volumes of
carbonic acid per cent. Good air should accordingly not take more than 1
c. c. of soda solution, air which takes already 2 c. c. being already bad.
In order practically to carry out this method of estimating carbonic acid
the following apparatus is required:--Several bottles capable of holding
2·210 c. c., and well stoppered (failing bottles of exactly the right
capacity Winchester quart bottles will answer); a small pair of bellows;
several colourless glass cylinders marked at 100 c. c. capacity--the
Nesslerising cylinders will answer for this purpose--a graduated pipette
or burette to deliver tenths of a c. c. of solution, the standard solution
of carbonate of soda, and the baryta water, which may be of moderate
strength.
The testing is managed thus: Winchester quart bottles having been made
clean are rinsed with distilled water, and allowed to drain a little. They
are then closed with their stoppers, and are ready for use. The operator
having provided himself with two or three of these bottles and a small
pair of bellows enters the room the air of which is to be tested. The
stopper is then removed from one of the bottles, and some air of the room
blown through with the bellows, and then the stopper is replaced, and the
bottle carried away to be tested.
The testing is done by pouring into the bottle 100 c. c. of clear baryta
water, shaking up for two or three minutes, and then pouring out into a
cylinder of colourless glass, and observing the depth of the turbidity in
various lights and against various backgrounds. The turbidity is to be
exactly imitated by means of the standard solution of carbonate of soda.
In order to imitate the turbidity produced by a Winchester quart full of
good air only 1 c. c. of this solution of carbonate of soda is required.
If 2 c. c. or more than 2 are required, the air is bad and the ventilation
is defective.
In place of the first c. c. of solution of carbonate of soda the carbonic
acid naturally present in a Winchester quart of good average air may be
used, and a little practice and intelligence will suggest the necessary
precautions.
_Estimation of the Oxygen._--To determine this Angus Smith has recourse to
the endiometer. Five or six of Bunsen's endiometers were used at once and
the mixed gases were exploded by means of a powerful battery and a
Ruhumkorff's coil. In his 'Inorganic Chemistry,' Miller thus explains the
principle upon which the action of the endiometer is based: "By means of
the endiometer various gaseous mixtures may be analysed with great
exactness. Many different forms of this instrument are in use. One of the
most convenient is Hoffmann's. It consists of a stout syphon tube. (See
next figure.) Into the sides of the tube, near the sealed end, two
platinum wires (_a_, _b_) are fixed for the purpose of transmitting an
electric spark through the cavity of the tube. The sealed limb is
accurately graduated to tenths of a c. c. or other suitable divisions.
Suppose it be desired to ascertain the proportion of oxygen in atmospheric
air. The instrument is first filled with mercury, after which a small
quantity of air is introduced; the bulk of the air is accurately measured,
taking care that the liquid metal stands at the same level in both tubes,
which is easily effected by adding mercury, or by drawing off the mercury
if needed, through the caoutchouc tube, which is fixed upon the small
inlet tube just above the bend, and which is closed by means of a screw
tap (_c_).
[Illustration]
A quantity of pure hydrogen, about equal in bulk to the air, is next
introduced, and the bulk of the mixture is then accurately measured. The
open extremity of the tube is now closed with a cork, below which a column
of atmospheric air is safely included. This portion of air acts as a
spring, which gradually checks the explosive force, when the combination
is effected by passing a spark across the tube by means of the platinum
wires. The mixture is then exploded by the electric spark. The remaining
gas now occupies a smaller volume, owing to the condensation of the steam
which has been formed. Mercury is, therefore, again poured in the open
limb until it stands at the same level in both tubes, and the volume of
the gas is measured a third time. One third of the reduction of the bulk
experienced by the gas will represent the entire volume of oxygen which
the mixture contained. Liebig's method is as follows. It is based upon the
fact that an alkaline solution of pyrogallic acid absorbs oxygen:
1. A strong measuring tube holding 30 c. c., and divided into one fifth or
one tenth c. c., is filled to two thirds with the air intended for
analysis. The remaining part of the tube is filled with mercury, and the
tube is inverted over that fluid in a tall cylinder widened at the top.
2. The volume of air confined is measured--a quantity of solution of
potash of 1·4 sp. grf. (1 part of dry hydrate of potash to 2 parts of
water), amounting from 1/40th to 1/50th of the volume of the air, is then
introduced into the measuring tube by means of a pipette with the point
bent upwards (see _drawing_), and spread over the entire inner surface of
the tube by shaking the latter. When no further diminution of volume takes
place the decrease is read off. The carbonic acid is thus removed.
[Illustration]
3. A solution of pyrogallic acid containing 1 gramme of the acid in 5 or 6
c. c. of water is introduced into the same measuring tube by means of
another pipette similar to the above. The mixed fluid (the pyrogallic acid
and the solution of potash) is spread over the inner surface of the tube
by shaking the latter, and when no further diminution of volume is
observed the residuary nitrogen is measured.
4. The solution of pyrogallic acid mixing with the solution of potash of
course dilutes it, causing thus an error from the diminution of its
tension; but this error is so trifling that it has no appreciable
influence upon the results. It may, moreover, be readily corrected by
introducing into the tube, after the absorption of the oxygen, a small
piece of hydrate of potash, corresponding to the amount of water in the
solution of the pyrogallic acid.
There is another slight error on account of a portion of the fluid
adhering to the inner surface of the tube, so that the volume of the gas
is never read off with absolute accuracy.
In conducting these endiometric experiments the necessary corrections for
temperature and barometric pressure must, of course, be made.
_Estimation of the Nitrogen._ The amount of this gas is usually determined
by deducting the aqueous vapours, oxygen and carbonic acid, from the
volume of air examined.
_Determination of Ammonia and Organic Matter._ These are best determined
by drawing a known volume of air through absolutely pure water. To obtain
this latter it is best to redistil distilled water, to reject the first
portions, then to add an alkaline solution of permanganate of potash, and
to discard any portions of the distillate which give the slightest
reaction with the Nessler test. The water through which the air is drawn
must be kept cool, and afterwards submitted to the proper tests, which
will be found under AMMONIA and WATER ANALYSIS. Mr Blyth says, "Solid
bodies such as vibrionic germs, dust, fungi, &c., may be obtained by using
an aspirator, and drawing the air either through a drop of glycerine or
water. Organic matter may also be obtained by suspending glass vessels
filled with ice water, over or in the places to be investigated, and
submitted to the microscope. High powers, such as immersion lenses, are
requisite for the investigation of germs," &c.
Of these germs Dr Angus Smith says:--"They may probably be divided into
many kinds--the useful and the deleterious, those which promote health and
those which bring disease. The idea of any of them bringing health is not
founded on anything positive, but we can scarcely imagine these numberless
forms to be all useless. The idea that they bring disease is, I think, one
well confirmed." See a paper by the same author "On the Air and Rain of
Manchester." 'Memoirs of the Literary and Scientific Society of
Manchester,' vol. x. See AIR, VITIATED.
=AIR-GAS.= Air deprived of its carbonic acid and moisture, and then
impregnated with the vapours of very volatile fluid hydrocarbons, such as
benzine and benzoline, can be used as an illuminating agent. It is
requisite, however, to use burners with wide openings, and to apply a low
pressure, because if the current be too rapid the flame becomes too much
cooled, and is readily extinguished. Apparatus for preparing air-gas have
been devised and constructed by Marcus, Mille, Methei, and others.
[Illustration]
=AIR-PUMP.= An instrument designed for the removal of air from closed
vessels. The simplest form of air-pump is the exhausting syringe, which
consists of a cylinder fitted with a stop-cock, and having a valve at the
bottom opening inwards. Another valve opening outwards is attached to a
piston working inside the cylinder, and by screwing the instrument on to a
vessel, and alternately elevating and depressing the piston, all except a
very small quantity of residual and comparatively inelastic air is pumped
out of the vessel (Figs. _a_ and _b_). The accompanying figures show
relative positions of the valve during (_a_) the elevation, and (_b_) the
depression of the piston. In the usual and more convenient form of
air-pump, a brass tube passes from the bottom of the syringe and
terminates in the centre of a disk of brass or glass ground accurately;
the vessel from which the air is to be exhausted has its edge very
accurately ground, and is mounted upon the plate as shown in the subjoined
figure.
[Illustration]
=Air-pump, Bunsen's Water.= (See figure on page 53.)
This consists of a wide glass tube, _a_, into which another tube, _b_,
_b'_, _b''_, passes air-tight. _c_ is an india-rubber tube connecting a
with the water supply, _d_ is a clamp to stop the flow of water through
_c_. _e_ is another clamp to regulate the flow, _f_ is a reservoir to
prevent any water which may accidentally come over from getting into _j_.
_g_ is a plug to let out any water from _f_. _h_ is a screw for connecting
a air-tight to a piece of tubing, which should pass 32 feet, if possible,
below the level of _a_. _i_ is a piece of strong india-rubber tubing to
connect the pump with the vessel to be exhausted. The water rushes in at
_c_ and down _h_, carrying bubbles of air with it till the exhaustion is
complete. The figure illustrates a common application of this pump to the
rapid filtration of liquids which ordinarily pass through paper with
difficulty. _a_ is represented as being about half full of water. _k_ is a
funnel fixed air-tight in the india-rubber stopper of the bell-jar _j_.
_l_ is a small cone of platinum foil to prevent the paper filter which
fits into it from being broken. _m_ is a plate of ground glass, _n_ is a
beaker to receive the filtrate.
[Illustration: Bunsen's water-air-pump.]
=Air-pump, Sprengel's.= This apparatus depends on the principle of
converting the space to be exhausted into a torricellian vacuum.
In the subjoined figure, _c_, _d_ is a glass tube longer than a barometer,
open at both ends, and connected by means of india-rubber tubing with a
funnel, A, filled with mercury and supported by a stand. Mercury is
allowed to fall in this tube at a rate regulated by a clamp at C; the
lower end of the tube, _c_, _d_, fits in the flask B, which has a spout at
the side a little higher than the lower end of _c_, _d_; the upper part
has a branch at _x_ to which a receiver R can be tightly fixed. When the
clamp at C is opened, the first portions of mercury which run out close
the tube and prevent air from entering below. As the mercury is allowed to
run down the exhaustion begins, and the whole length of the tube from _x_
to _d_ is fitted with cylinders of air and mercury, having a downward
motion. Air and mercury escape through the spout of the bulb B, which is
above the basin H, where the mercury is collected. It is poured back from
time to time into the funnel A, to be repassed through the tube until the
exhaustion is complete.
[Illustration: Sprengel's air-pump.]
=AIRY'S (Dr.) NATURE'S MEDICAL TREATMENT= is the title of a pamphlet which
recommends four secret remedies against 166 diseases:
_a._ The Pain Expeller, a mixture of about 35 parts of tincture of
capsicum, 20 parts of diluted spirit, and 20 parts of spirit of ammonia.
_b._ Sarsaparillian, a fluid extract of sarsaparilla and China root,
containing 1 per cent. of iodide of potassium.
_c._ Pills composed of powdered iron, jalap resin, jalap powder, and marsh
mallow powder, made into a mass with some bitter extract. Each pill weighs
0·1 gramme.
_d._ Calming Pastilles are thick, hard tablets, composed of sugar, with
oil of anise, and coloured with liquorice juice. (Hager.)
=AKUSTICON= (an ear essence). A proved remedy for every kind of ear
disease, by Pserhofer. This may be imitated by dissolving in common
glycerine one fifth of its weight of fir tar, filtering, and adding a few
drops of cajeput oil dissolved in spirit (Hager.)
=AL-.= [Ar.] An inseparable article equivalent to the English _the_. It is
found in many chemical and other words derived from the Arabic; as
alchemy, alcohol, alembic, almanac, &c.
=AL'ABASTER.= _Syn._ ALBÂTRE, Fr.; =Alabas'ter=, =Alabastri'tes=,
=Alabas'trum=, L. A soft, white species of calcareous and of gypseous
stone, used by sculptors. There are several varieties, all of which may be
ranged under two heads:--
1. CALCA''REOUS ALABASTER; ORIENT'AL, A.; CALC-SIN'TER. A sub-variety of
carbonate of calcium, formed by the deposition of calcareous particles in
the caverns of limestone rocks. It has a foliated, fibrous, or granular
structure, and a pure, soft, rich, semi-translucent whiteness, generally
agreeably variegated with undulating zones or stripes of various shades of
yellow, red, or brown. This variety is that most esteemed by sculptors,
and for the manufacture of alabaster ornaments. The ancients used it for
ointment and perfume boxes. At the baths of San Filippo (Tuscany), the
process of its formation may be examined by the observer. The natural
spring of boiling water holds carbonate of lime in solution by means of
sulphuretted hydrogen, which, escaping into the air, leaves the lime as a
precipitate, which is gradually deposited in a concrete form. (M. Alex.
Brogniart.)
2. GYP'SEOUS OR COMMON ALABASTER; GYPSUM. A natural hydrated sulphate of
calcium, containing a little carbonate of calcium. That from the quarries
of the Paris basin contains about 12% of the latter substance. When
calcined or roasted, and powdered, it forms the substance known under the
name of PLASTER OF PARIS. The more compact, fine-grained specimens of this
variety are, like the preceding one, sculptured into almost numberless
articles of ornament and utility, such as vases, clock-stands, statuettes,
&c. The inferior kinds only are manufactured into the 'plaster of Paris'
of the shops. The best specimens are obtained from the lower beds of the
gypsum quarries, and are white, and granular, not unlike Carrara marble.
It takes a high polish; but from its softness and liability to become
discoloured, articles formed of it require more careful treatment than
even those of 'calcareous alabaster.'
Alabaster is wrought, turned, and fashioned, in a nearly similar manner to
the softer varieties of marble. The tools resemble those employed for the
like operations in ivory and brass. Machinery is now often applied to this
purpose.
Alabaster is polished, first with pumice-stone, and then with a paste or
pap made of whiting, soap, and milk or water; and lastly, with dry
flannel. A better method, however, is to rub it first with dried
shave-grass (equisetum), and afterwards with finely powdered and sifted
slaked lime formed into a paste with water. The surface is then 'finished
off' by friction with finely powdered talc or French chalk, until a satiny
lustre is produced, or with putty powder, in a similar way to marble.
Alabaster is engraved with tools resembling those employed for other soft
minerals. It is etched by covering every part of the surface, except that
to be acted on, with a solution of white wax in oil of turpentine (1 to
4), thickened with a little finely powdered white lead, and subsequent
immersion in water acidulated with acetic acid or hydrochloric acid, for
the calcareous variety; and in spring water, for 20 to 50 hours (according
to the effect desired), for the gypseous variety. The varnish is washed
off with oil of turpentine, and the etched parts carefully brushed over
with finely powdered gypsum.
Alabaster is joined and repaired by means of white of egg, or rice glue,
thickened with finely powdered quicklime; or by a paste of newly baked and
finely powdered gypsum, mixed up with the least possible quantity of
water.
Calcareous alabaster is usually cleaned with a brush and warm
soap-and-water, or with tepid water to which a few grains of carbonate of
soda or of ammonia have been added; followed in either case by rinsing in
clean water. If much discoloured, thoroughly cover the article with a
paste of freshly slaked lime and water, and let it remain twenty-four
hours; then wash off the paste with soap and water, rubbing hard the
stains.
Delicate objects in gypseous alabaster can only be safely cleaned with
benzol, or with pure oil of turpentine. If necessary, the surface must be
repolished. Grease spots may be removed from either variety with a little
benzol or oil of turpentine.
Alabaster is occasionally stained or coloured, and, for the calcareous
variety, in a similar way to marble, except that heat is not employed; and
for the gypseous variety, in the manner noticed under PLASTER OF PARIS.
The gypseous variety is also bronzed and hardened in a similar way to that
adopted for casts in the latter substance.
_Obs._ Gypseous alabaster is dissolved by water; and the beauty of both
varieties is almost irrecoverably destroyed by grease, coloured oils,
varnishes, smoke, &c. It is, therefore, unfitted for garden ornaments, or
other objects exposed to the rain or weather, unless it be painted or
bronzed; and is even then very perishable. Contact with acids, alkalies,
and ammoniacal and sulphurous fumes, also injure, and, if prolonged,
destroy it. Even an uncorked phial of smelling-salts placed on a
mantel-piece beside an alabaster vase will soon destroy its beauty. Thus,
all delicate objects in alabaster should be protected by a glass shade.
=Alabaster, Orient'al= (Factitious). Figures, basso relievos, &c., of
considerable hardness and beauty, may be formed by imitating the process
adopted at the baths of San Filippo, before referred to.
_Proc., &c._ Moulds of sulphur are placed either vertically or obliquely
in an open tub or cistern, having a freely perforated bottom. Surmounting
the whole are two or more pieces of wood in the form of a cross or star.
The sulphurous calcareous water, falling on this cross, is scattered into
spray or streamlets, and losing the gaseous portion which holds the lime
in solution, deposits it in the form of oriental alabaster on the surface
of the moulds. In from 1 to 4 months, according to the nature of the
article, a sufficiently thick deposit is obtained. The object is then
removed from the mould, and trimmed and polished. It is found that the
more vertical the position of the mould, the finer is the grain of the
resulting deposit. The water of the Spring of San Filippo may be exactly
and easily imitated by the chemist; and the whole process offers a new and
valuable ornamental art for the amusement and profit of the ingenious and
enterprising.
=Alabaster, Shand's Chinese.= Carbonate of lime. (Chandler.)
=Alabaster Tablets, John Swine's Chinese.= Carbonate of lime. (Chandler.)
=ALAMODE'= ([)a]l-[)a]h-m[=o]dé). [Fr., _à la mode_.] According to the
prevailing mode or fashion. In _cookery_, applied to several dishes, but
more particularly to one of beef (alamode beef), commonly shortened by the
lower class of Londoners into "alamode." See BEEF, STEWING, &c.
=ALAN'TINE.= [Eng., Fr., Ger.] _Syn._ ALANTI'NA, L. A substance identical
with inulin, found in the roots of garden angelica ('angelica
archangelica,' Linn.).
=ALBA'TA.= [L., Eng.] A name given to several alloys resembling silver.
See ALLOYS, GERMAN SILVER, &c.
=ALBION= (Parisian). "Will preserve the skin white and free from
wrinkles." An aromatic water with chloride of lead and calomel suspended
in it. (Landerer.)
=ALBOLITH.= A cement powder prepared by W. Riemann, Breslau. Made with
calcined magnesia (obtained from magnesite) and chloride of magnesium. It
is recommended for painting walls, stairs, and wooden articles. (Hager.)
=ALBU'MEN.= [Eng., L.] _Syn._ ALBUMIN; ALBUMINE, Fr.; EIWEISS, EIWEISTOFF,
Ger. Literally, the white of egg; a peculiar nitrogenous substance which
enters largely into the composition of animal bodies. It abounds in the
blood, muscles, bones, coagulable lymph, vitreous and crystalline humour
of the eye, fluid of dropsy, &c. The white of egg consists of nearly pure
albumen dissolved in water.
A substance identical with albumen is found in many vegetables. It enters
largely into the composition of all the emulsive seeds. According to
Seguin, it exists in considerable quantity in all those vegetables and
fruits that afford a vinous liquor without the addition of yeast.
_Prep._ The white of egg and the serum of blood, when strained through
muslin, furnish albumen, in solution, in a sufficiently pure state for all
the ordinary purposes of the arts. Pure solid albumen may be prepared as
follows:--
1. Agitate strained white of egg with 10 or 12 times its bulk of alcohol,
collect the precipitated flocculi on a muslin filter, and suffer it to dry
at a temperature not exceeding 120° Fahr.
2. Add a little water to white of egg, mix, filter, exactly neutralise
with acetic acid, and then largely dilute with pure cold water; the
precipitate which falls may be collected on a filter and washed. Strained
serum of blood may be used instead of white of egg, in both the above
forms.
_Comp._, _&c._ The following is the composition of albumen according to
Lieberkühn:--
Carbon 53·3
Hydrogen 7·1
Nitrogen 15·7
Oxygen 22·1
Sulphur 1·8
----
100·0
Chatin found iodine in the white of egg; it also contains chloride,
sulphate, phosphate, and carbonate of sodium, phosphate of calcium, and
traces of potassium in it; but, unlike the sulphur, none of these
substances form a constituent part of pure albumen, though probably always
present in white of egg.
_Prop._ Pure solid albumen (unaltered by heat) is nearly colourless,
inodorous, and tasteless; scarcely soluble in water, but readily so in
water, containing an exceedingly small quantity of caustic soda or potash,
and in a strong solution of nitrate of potassium. When dried by a gentle
heat it shrinks into a translucent horny mass; and when exposed to a
sufficient temperature, yields the usual ammoniacal odour and products of
animal matter. Its solution (as white of egg) is solidified or coagulated
by a heat of from 145° to 165° Fahr., forming a white, opaque mass; when
very dilute, on boiling (only) it separates in fine light flocks. When
thus coagulated, it is insoluble in water at a less temperature than 302°
Fahr. (Wöhler and Vögel), unless alkalised. Ordinary solutions of albumen
give precipitates with sulphuric, hydrochloric, nitric, and metaphosphoric
acids, with tannin and astringent solutions, and with most of the metallic
salts; but are not affected by either acetic acid or tribasic (common)
phosphoric acid. Alcohol, in quantity, also precipitates albumen. Strong
oil of vitriol turns it black in the cold, but on applying a gentle heat,
a gorgeous, red-coloured liquid is produced. Strong hydrochloric acid
gives a deep violet-blue solution. White of egg or serum exposed in a thin
stratum to the air, dries up into a pale, yellow, gum-like substance, and
in this state may be kept for any length of time, retaining its property
of redissolving when immersed in slightly warm water.
_Tests._--1. Both heat and alcohol (or strong spirit) coagulate it:--2. A
solution of perchloride of mercury dropped into a fluid containing
albumen occasions a white precipitate:--3. Subacetate of lead acts in the
same way. Either of the last two will render turbid a solution containing
only the 1-2000th part of fresh white of egg, or the 1-10,000th part of
dry albumen:--4. Tannin and tincture of galls give yellow, pitchy
precipitates:--5. If dry caustic potash or soda be triturated with either
liquid or solid albumen, ammoniacal fumes are evolved, and the mixture on
calcination yields ferrocyanide of potassium:--6. Its coagulability by
heat, and its incoagulability by acetic acid, distinguish it from casein.
_Uses, &c._, Independently of its value as an alimentary substance,
albumen is largely employed in photography as a glaze or varnish, for
fixing colours in calico printing, as a cement, &c., and more particularly
as a clarifier for wines, syrups, vegetable solutions, and other liquids.
Its efficacy for the last purpose depends on its entangling the impurities
in its meshes during coagulation, and either rising to the surface with
them as a 'scum,' or sinking with them as a precipitate. In France it is
prepared on an extensive scale, at the abattoirs, by being spread in thin
layers to dry; the source of supply being of course the stream of the
blood of the slaughtered animals. When the liquid operated on does not
spontaneously coagulate albumen, it is necessary to apply heat to it. In
cases of poisoning by the mineral acids, corrosive sublimate, nitrate of
silver, sulphate of copper, bichloride of tin, or sugar of lead, the white
of egg (or indeed the yolk as well) is one of the best antidotes that can
be administered.
=Albumen, Flake.= _Syn._ ALBUMEN IN POWDER, SOLID A., SOLUBLE A.,
PLANTER'S A. _Prep._ Expose strained white of egg or serum of bullock's
blood, in a thin stratum, to a current of dry air, until it concretes into
a solid transparent substance, resembling horn. In this state it may be
kept any length of time, or it may be further dried until brittle, and
then reduced to coarse powder.
_Use._ It is extensively employed as a 'clarifier' in the sugar
plantations of the West Indies, and elsewhere. It is prepared for use by
soaking and stirring it with cold water until it is dissolved, when it is
whisked to a froth in the usual way, and agitated with the liquid to be
clarified.
=Albumen, Iodised.= 1. To the white of every egg employed add 7-1/2 grains
of iodide of potassium dissolved in an equal weight of distilled water.
Beat the mixture to a froth, let it stand until insoluble matters have
settled, pour the clear portion into a wide-mouthed bottle, and keep in a
cool place. 2. Dissolve 50 grains of iodide of potassium and 10 grains of
bromide of ammonium in 2-1/2 oz. of distilled water, and add 120 minims of
strong liquor ammoniæ. Add this solution to 10 oz. of albumen, let the
mixture stand to settle, and filter. This preparation is said to keep good
for a long time.
=Albumen, Solution of (B. P.).= Take of white of one egg; distilled water,
four fluid ounces. Mix by trituration in a mortar, and filter through
clean tow, first moistened with distilled water. This solution must be
recently prepared.
=Albumen, Vegetable.= This substance, long considered to be a distinct
proximate principle peculiar to the vegetable kingdom, has been shown, by
recent researches, to be identical with animal albumen. It is particularly
abundant in carrots, turnips, cabbages, green stems of peas, and
oleaginous seeds.
=ALBU'MEN.= In _botany_, the solid, fleshy, or horny substance found in
many seeds, between the integuments and the embryo. It is the part that
furnishes the flour of the 'cereals,' the flesh of the 'cocoa-nut,' and
the great mass of the seeds of coffee and other vegetables. However
poisonous the plants which produce it may be, this substance is never
deleterious.
=ALBUMENISED PAPER.= A French paper highly glazed, having a fine surface,
and made by Rive; a German paper having a more uniform texture, and made
by Saxe; also a paper by Towgood, are recommended for the preparation of
albumenised paper. Positive paper may be albumenised as follows:--Add 15
grains of finely pulverised common salt to the white of every egg used,
and whisk until the mixture is entirely converted into a white froth.
Allow this froth to stand in a glazed earthenware pan which must be rather
larger than the sheets of paper to be albumenised, for about twelve hours.
At the end of this pour the clear portion of the liquid into a flat
porcelain tray. Mark the inferior side of the paper, slightly damp it,
lift it by its ends, and float it carefully on the prepared albumen,
keeping its inferior and dry side uppermost. Then raise the paper at each
end, and if any air bubbles are seen remove them with a card or brush and
replace the paper in the bath. Remove the paper from the bath and suspend
it at the corners by clips. Albumenised paper should be kept dry by
enclosing it in tin or zinc cases.
=ALBUMENOIDS.= A term applied to albumen, fibrin, casein, and similar
bodies.
=ALBU'MENOUS.= _Syn._ ALBUMINO'SUS, L.; ALBUMINÉ, ABUMINEUX, Fr.;
EIWEISSTOFFHALTIG, Ger. Formed of, containing, or having the properties of
albumen.
=Albuminous Plants=. In _botany_, all plants whose seeds contain albumen
in a separate state; as in the cereals, palms, &c.
=Albuminous Principles _or_ Substances.= Albumen, casein, fibrin, gluten,
&c.
=ALBURN'UM.= [L.] _Syn._ ALBURN*; SAPWOOD. In _botany_, the white and
softer parts of the wood of exogenous plants, lying between the inner bark
and the heartwood. It consists of empty or nearly empty tubes or cells,
which gradually acquire solidity by the deposition of resins, tannin, and
other products of vegetation, and in time becomes wood. It is through the
alburnum that the ascending sap chiefly flows.
=ALCARAZ'ZA.= [Sp.] A species of porous earthenware, or a vessel formed of
it, made in Spain from a light, sandy marl, and but slightly fired. Their
value as 'coolers' arises from the copious evaporation of the water, which
gradually transudes. A similar ware and articles are made in France, under
the name of HYGROCERA'MEN; and in England, under the names of POROUS WARE,
WATER COOLERS, WINE COOLERS, BUTTER COOLERS, &c. The following are forms
said to be used in our potteries:--
_Prep._ 1. Take of sandy marl, 2 parts; brine, q. s.; make a dough, and
then knead in of common salt, in fine powder, 1 part. Bake the pieces
slowly, and lightly.
2. Good clay, 2 parts; fine siliceous sand, 3 parts; brine, q. s.; common
salt, 1 to 2 parts; as before.
3. Powdered clay, 2 parts; powdered charcoal, 3 parts (by weight); water
q. s. to form a stiff dough. The kilning must be so arranged that the heat
is applied gradually, and the vessels exposed to a current of hot air; and
it must be continued until all the charcoal is burnt out, carefully
avoiding over-firing.
=AL'CHEMY= (-k[)i]m-). _Syn._ AL'CHYMY (-k[)i]m-); HERMETIC ART*;
ALCHEM'IA, ALCHYM'IA, L.; ALCHIMIE, Fr.; ALCHEMIE, Ger.; ALCHIMIA, It. The
romantic forerunner of the modern science of chemistry. An imaginative art
or science, having for its objects the discovery of a substance
(PHILOSOPHER'S STONE) capable of transmuting the baser metals into gold--a
panacea, or universal remedy (ELIXER VITÆ), by which disease and death
were to be avoided by its possessor--an alkahest, or universal solvent--a
universal ferment; and other like absurdities. A mixed metal formerly used
for utensils was also called by this name.
=AL'COHOL.= C_{2}H_{6}O. [Eng., L.; B. P.] _Syn._ AL'KOHOL, Eng., L.;
ALCOÖL, ALCOHOL, Fr.; ALKOHOL, HÖCHST RECTIFIEIRTER WEIN-GEIST., Ger.;
ALCOÖLE, It. A term commonly applied to one kind of spirit--that obtained
by the distillation of any fermented saccharine liquid, and forming the
characteristic principle of wines, beers, spirits, and other intoxicating
liquors.
_Etym._ Kohol, a Hebrew-Syriac word, is the name given to a preparation of
powdered antimony used by Oriental ladies to paint their eyebrows. In
course of time this term was applied to other fine powders, and ultimately
to highly rectified spirits.
_Hist., &c._ Although the art of distillation was probably known at a
comparatively early age of the world, the preparation of pure rectified
spirit is a discovery of modern times. It was not until the 13th century
that Raymond Lully first showed the way to concentrate spirit by means of
carbonate of potash; after which date pure concentrated spirit gradually
rose into note as an article of trade and commerce in Europe. In the 16th
century its distillation was in common practice in these countries.
(Burns.) By means of chloride of calcium, Dr Black obtained alcohol of sp.
gr. 0·800 (about A.D. 1760); and Richter afterwards procured it of a sp.
gr. so low as 0·796 at 60° Fahr. (Crell's 'Annals,' 1796.) Lavoisier first
demonstrated the composition of alcohol (about 1780). Its analysis was
subsequently perfected by M. Saussure, jun., and confirmed by MM. Dumas
and Boullay, and Gay-Lussac; and by many others since.
_Nat. Hist._ Alcohol is peculiar to the organic kingdom, being exclusively
produced, in the natural way, by the process of fermentation.
_Sources, &c._ Dilute alcohol may be procured, by the ordinary process of
distillation, from all fermented liquors. When drawn from wine (as in
France), it constitutes BRANDY; when from the refuse juice of the
sugar-cane, it is called RUM; when from malt, grain, or molasses (as in
England), it is called MALT, RAW-GRAIN or MOLASSES SPIRIT; and when from
rice or palm-wine, ARRACK. Brandy, rum, Hollands, and whisky, contain only
about half their volume of alcohol; and gin much less. When distilled from
any of these spirituous liquors, the alcohol contains, besides water,
variable quantities of essential oils, ethers, and other flavouring
matters, which, by one or more redistillations with charcoal or lime, it
for the most part loses, and then becomes commercial spirit of wine. By a
further rectification from chloride of calcium, lime, carbonate of potash,
or any other substance having a strong affinity for water, the water is
retained, and a strong spirit passes over containing not more than 10 per
cent. of water. By repeating the process, and using the proper
precautions, it may be obtained almost entirely free from water, and is
then called absolute or anhydrous alcohol.
_Preparation I._ Of _Absolute Alcohol_:--
_a._ Alcohol (highly rectified spirit), of 85% (sp. gr. ·835 to ·822), is
mixed, in a tubulated retort, with about half its weight of fresh-burnt
quick-lime, in coarse powder; and the whole, after securely stopping the
neck with a cork, and agitation, is allowed to repose for several days.
The alcohol is then carefully distilled off, drop by drop, by the heat of
a water bath, until the weight of the distillate nearly equals that of the
'anhydrous alcohol' in the spirit operated on. The sp. gr. of the product
should be ·795 or ·796; but by carefully repeating the process with the
distillate and a fresh quantity of lime, and prolonging the last digestion
with the latter for several weeks, absolute alcohol of the sp. gr. ·79381
at 60° Fahr. may be easily obtained.
_b._ (Drinkwater; Fownes.) The strongest rectified spirit of wine is
digested in a stoppered bottle for several days, with about half its
weight of anhydrous carbonate of potash, in powder, frequent agitation
being had recourse to; the alcohol, after repose, is then decanted, and
treated with sufficient fresh-burnt quick-lime to absorb the whole of the
spirit. After 48 hours' digestion, the spirit, when distilled, will have
the sp. gr. ·793 at 60° Fahr.
_c._ (Liebig; Ure.) Alcohol of about 90% is saturated with fused chloride
of calcium, in powder, and after repose for a few hours in a stoppered
bottle, is submitted to distillation as before. The product should nearly
equal the quantity of dry alcohol in the sample. Ure recommends equal
weights of the spirit and chloride to be taken; and the process to be
stopped as soon as about half the volume of the spirit employed has passed
over, or the distillate acquires a higher sp. gr. than ·791 at 68°, or
·796 at 60° Fahr.
_d._ (B. P. 1867.) Take of rectified spirit, 1 pint; carbonate of potash,
1-1/2 ounce; slaked lime, 10 ounces. Put the carbonate of potash and
spirit into a stoppered bottle and allow them to remain in contact for two
days, frequently shaking the bottle. Expose the slaked lime to a red heat
in a covered crucible for half an hour, then remove it from the fire, and,
when it has cooled, immediately put the lime into a flask or retort, and
add to it the spirit from which the denser aqueous solution of carbonate
of potash, which will have formed a distinct stratum at the bottom of the
bottle, has been carefully and completely separated. Attach a condenser to
the apparatus, and allow it to remain without any external application of
heat for twenty-four hours; then applying a gentle heat, let the spirit
distil until that which has passed over shall measure 1-1/2 fluid ounce;
reject this, and continue the distillation into a fresh receiver until
nothing more passes at a temperature of 200° Fahr.
_e._ (Poggendorff.) Saturate alcohol with caustic potash, then add half
its volume of water, and distil at a low temperature.