Ammoniac.
QUALITIES. _Form_, masses composed of fragments, of tears, yellow on the
surface, and white within; _Taste_, a nauseous sweet, followed by a
bitter flavour; _Odour_, faint but not unpleasant. _Specific gravity_,
1·200. CHEMICAL COMPOSITION. Gum-resin, gluten, and some volatile
matter. SOLUBILITY. It is partly soluble in water, vinegar, alcohol,
æther, and in the solutions of the alkalies; when triturated with water
a milky liquor is formed, which is a solution of gum holding the resin
in suspension, and if the yolk of an egg be employed the mixture is more
permanent; water appears to be its proper solvent. USES. Stimulant,
antispasmodic, and expectorant: in large doses gently purgative and
sometimes diuretic; after the exhibition of smart purgatives, in
combination with rhubarb, it proves valuable in mesenteric affections by
correcting the viscid secretion of the intestines; dissolved in nitric
acid, it is said to prove an excellent expectorant in cases where large
accumulations of purulent or viscid matter exist with feeble and
difficult expectoration. See _Form: 140_. FORMS OF EXHIBITION. In
solution, see _Mist: Ammoniac:_ it may also be given when dissolved in
the _Liquor ammoniæ acetatis_; ʒij of the former may be dissolved in
℥iij of the latter; or it may be exhibited in pills with bitter
extracts, myrrh, and other gum-resins; if rubbed with camphor a mass is
at once produced very suitable for pills; vinegar renders it soft, and
adapts it for plasters. DOSE, grs. x to xxx. OFFICINAL PREPARATIONS.
_Mist: Ammoniac:_ L.D. _Pil: Scillæ co:_ L.E. (=B=) _Emplast: Ammoniac:_
L. _Emplast: Gummos:_ E. _Emplast: Ammoniac: cum Hydrargyro_. L.
ADULTERATIONS. Two varieties are met with in the market, that in tears,
_guttæ ammoniaci_, ought to be white, clear, and dry; and that in lumps,
_lapis ammoniaci_, which sells for one-third the price of the former,
being very impure, is generally adulterated with common resin, for which
it may be purified by softening the mass in a bladder which is immersed
in boiling water, and straining it while fluid.
AMMONIÆ SUB-CARBONAS. L. Carbonas Ammoniæ. E.D.
_Sub-carbonate of Ammonia._
QUALITIES. _Form:_ white, semi-transparent masses, of a striated or
crystalline aspect, which, on exposure to air effloresce; _Odour_,
pungent and peculiar; _Taste_, acrid but cooling. CHEMICAL COMPOSITION.
It will be found to vary materially in its composition according to the
temperature employed for its preparation; the quantity of alkali varying
from 20 to 50 per cent. Mr. Phillips considers the _Sub_-carbonate of
ammonia to be a _Sesque_-carbonate, composed of 3 atoms of carbonic
acid, 2 atoms of ammonia, and 2 of water; or that it is a definite
compound of _Carbonate_ and _Bi-carbonate_, one atom of each, with two
atoms of water; one hundred parts, by experiment, consist, of 54·2
_carb: acid_, 29·3 _Ammonia_, and 16·5 _water_; if we consider it as a
_Sesque-carbonate_, its constitution, according to Dr. Wollaston’s
scale, will be 55·72 _Carbonic Acid_, 29 _Ammonia_, 15·28 _water_.
SOLUBILITY. According to Duncan it is soluble in twice its weight of
cold water; Mr. Phillips states four times; the mean of these will be
found nearly correct. Its solubility however is increased by increase of
temperature, but when dissolved in boiling water it effervesces, and
undergoes a partial decomposition; it is quite insoluble in alcohol, and
hence on the addition of spirit to a strong solution, a dense coagulum
is produced. INCOMPATIBLE SUBSTANCES. It is decomposed by _acids_,
_fixed alkalies_, and their _sub-carbonates_, _lime_, _solution of
muriate of lime_, _magnesia_, _alum_, _super-tartrate of potass_, and
all the _acidulous salts_, _sulphate of magnesia_, _acetate_,
_sub-muriate_, and _oxy-muriate of mercury_, _acetate_, and _sub-acetate
of lead_, and the _sulphates of iron and zinc_. If it be added to
decoctions and infusions they must be previously cooled. FORMS OF
EXHIBITION. Since by exposure to air its virtues are impaired, it ought
not to be kept in powdered mixtures; in the form of pill it is preserved
much longer, especially if it be combined with some vegetable extract.
USES. It is stimulant, antispasmodic, diaphoretic, powerfully antacid,
exceeding in this respect the fixed alkalies, and in large doses it is
emetic. It is highly useful as a stimulant in those gastric affections
which supervene habits of irregularity and debauchery; combined with
opium it affords a powerful resource in protracted diarrhœa attended
with debility of the alimentary canal: and in cases of muscular atony so
frequently witnessed, as the _sequela_ of chronic rheumatism, ammonia,
in large doses, offers the best remedy; I have moreover witnessed the
beneficial effects of this remedy in hoarseness depending upon relaxed
states of the throat. In typhus fever it has been particularly
recommended by Huxham, Pringle, and many other physicians, and some have
considered it superior to any other stimulant upon such occasions. It is
also useful in syncope and hysteria, in the form of smelling salts;[366]
with respect to its application for making saline draughts, see _Acid:
Citricum:_ DOSE, grs v to ℈j: to produce emesis ʒss. See _Form. 48, 49,
83, 152_. _Officinal Preparations._ _Liquor Ammoniæ sub-carbonatis_, L.
_Liquor Ammoniæ acetatis_ (=I=) L.E.D. _Liniment: Ammoniæ
Sub-carbonatis._ L. _Cuprum Ammoniatum_, (=I=) L.E.D. ADULTERATIONS.
This salt ought to be entirely volatilized by heat; if any thing remain
it may be considered impure; it ought also to be free from all fetor;
should this not be the case it may be corrected by subliming it in
conjunction with powdered charcoal; there is at present a large quantity
of this impure article in the market, which has been manufactured from
the residue sold by the gas light companies.[367] When long exposed to
the air, it becomes opaque and friable, and the excess of ammonia, upon
which its odour depends, escapes, carbonic acid is absorbed, and an
inodorous bi-carbonate remains, consisting of carbonic acid 55·70,
Ammonia 21·52, and water 22·76, or 2 atoms of carbonic acid, 1 atom of
ammonia, and 2 atoms of water.
AMMONIÆ MURIAS. L.E. Sal Ammoniacum. D.
vulgo _Sal Ammoniac_.
QUALITIES. _Form_, dense striated concavo-convex cakes which are
persistent in the air, or crystallized conical masses; in this latter
form it generally contains other salts, especially muriate of lime,
which render it deliquescent. _Taste_, bitter, acrid, and cool. CHEMICAL
COMPOSITION. In consequence of the present unsettled opinions respecting
the nature of muriatic acid and ammonia, and the changes which they
undergo by combination with each other, the composition of this salt is
involved in some obscurity. According to Dr. Thomson, it consists of
equal volumes of muriatic acid gas and ammoniacal gas, although he has
subsequently observed that from the peculiar properties of the
substance, it may be a compound of _Chlorine_ and _Ammonium_ (the
hypothetical base of ammonia.) Unlike all the other ammoniacal salts, it
does not undergo decomposition by heat. SOLUBILITY, f℥j of water at 66°
dissolves about two drachms and a half; at 212° it dissolves its own
weight; it is also soluble in 4½ parts of alcohol; its solution in water
is accompanied by considerable reduction of temperature. INCOMPATIBLE
SUBSTANCES. The sulphuric and nitric acids unite with the ammonia, and
disengage the muriatic acid, whilst ammonia is disengaged by the action
of potass and its carbonate, carbonate of soda, lime, magnesia, &c.
which combine with its muriatic acid; with oxy-muriate of mercury it
combines and increases its solubility, see _Hydrarg: Oxy-murias_. When
united with acetate of lead, it decomposes it, and a muriate of lead is
precipitated. It is obvious also that nitrate of silver, and all the
metallic salts whose bases form insoluble compounds with muriatic acid,
are incompatible with it. USES. Rarely employed as an internal remedy,
externally it is employed in lotions, either for the cold produced
during its solution, in which case it should be applied as soon as the
salt is dissolved, or for the stimulus of the salt, on which principle
it acts as a powerful discutient in indolent tumours (_Form. 146._) It
is also an ingredient in a very useful plaster, in which it undergoes
chemical decomposition; this plaster consists of _Soap_ ℥j, _lead
plaster_, ʒij, liquified together, to which, when nearly cold, are added
of _muriate of ammonia_ finely powdered ʒss. The alkali of the soap
enters into combination with the muriatic acid of the muriate of
ammonia, and forms thereby muriate of potass, or soda, and ammoniacal
gas (on which the virtue of the plaster depends) is slowly but
abundantly liberated, acting as a powerful stimulant and rubefacient: it
should be applied immediately after it is formed, and be renewed every
twenty-four hours, otherwise the intention is lost; (_Pharmacopœia
Chirurgica._) I have often applied this plaster with evident advantage
to the chest in pulmonary affections, and I wish to recommend it to the
attention of practitioners. It is very useful also in that rheumatic
affection of the muscles of the chest, which is so frequently met with
in persons in advanced life; during the last winter I was consulted in
two cases where the distress after exercise was so considerable as to
resemble angina pectoris. OFFICINAL PREPARATIONS. _Ammoniæ Sub-carbonas_
(=I=). L.E.D. _Liquor: Ammoniæ_ (=K=). L. _Aqua Ammoniæ._ E.D. _Hydrarg:
præcip: alb:_ (=I=). L. _Alcohol Ammoniatum_, (=I=). E.D. _Ferrum
Ammoniat:_ (=G=). L.E.D. ADULTERATIONS. This salt, if pure, may be
entirely volatilized by a low heat; the _sulphate of ammonia_ however,
as it is also volatile, cannot be discovered except by the muriate of
baryta, which will indicate its presence by a copious precipitate.
AMYGDALÆ DULCES. {Varieties of “Amygdalus Communis.”
AMYGDALÆ AMARÆ. {Sweet and Bitter Almonds.
QUALITIES. The _sweet almond_ is inodorous, and has a sweet, bland
taste; the _bitter almond_,[368] when triturated with water, has the
odour of the peach, and a pleasant bitter flavour. CHEMICAL COMPOSITION.
Boullay has lately confirmed the analogy which Proust had stated to
exist between the emulsion of sweet almonds and human milk, viz. the
former consists of sweet oil 54, albumen 24, sugar 6, gum 3, with traces
of acetic acid; the indigestible property of the almond depends upon its
albuminous matter. The _bitter almond_, in addition to those
constituents, contains hydro-cyanic acid, (Prussic acid,) in union with
a peculiar volatile oil, upon which its narcotic properties depend; but
this deleterious element is so modified by the natural state of
combination in which it exists with sweet oil and albumen, that they may
be eaten without inconvenience. The bitter almond has long been regarded
as an antidote to drunkenness; Plutarch states it as a fact on the
authority of his physician Claudius. Other bitters were however supposed
to possess similar powers in this respect, hence the _Poculum
Absinthiatum_ to which we have before alluded. See page 79. Both sorts
of almonds yield by expression a large quantity of fixed oil, which is
perfectly mild. See _Oleum Amygdal_. The water distilled from the bitter
almond, when strongly impregnated, has been found to exert a deleterious
action on the human body, and to prove fatal to many animals.
SOLUBILITY. By trituration with water a milky mixture is produced, (_an
emulsion_), for which purpose the sweet almonds should be previously
freed from their cuticle, (_blanched_), and this ought to be performed
by infusing them in tepid water; for when hot it separates a portion of
their oil, as is evident from their being thus rendered yellow, and the
emulsion is therefore more liable to ferment, and be decomposed. ℥ij of
almonds saturate about f℥vj of water; since however this extemporaneous
preparation is tedious and inconvenient, the London Pharmacopœia very
judiciously directs a confection to be ready prepared, ʒj of which, when
triturated with f℥j of water, immediately forms an elegant emulsion. See
_Mistura Amygdal_. Almonds form a useful intermedium for suspending in
water many substances which are of themselves not miscible with it, as
camphor, and several of the gum-resins; they also assist in the
pulverization of refractory substances, as Ipecacuan, &c. OFFICINAL
PREPARATIONS. _Confectio Amygdalarum._ L. _Emulsio Camphoræ_ (=M.=) E.
_Emulsio Acaciæ Arab:_ E. D.
AMYGDALÆ PLACENTA. _Almond Cake_ is the substance left after the
expression of the oil, which when ground forms ALMOND POWDER, so
generally used for washing the hands.[369]
OIL OF BITTER ALMONDS. For obtaining this oil, the expressed cake is
submitted to distillation, when a highly volatile, pungent, oil passes
over. See _Oleum Amygdalæ Amaræ_.