PHARMACIf. 
soluble in water are mixed with, and sus- 
pended in, watery fluids, by means of such 
viscid substances as mucilages and syrups. 
Emulsio amygdalae communis, Ediu. lac 
amygdal®, Lond. almond emulsion. 
Emulsio arabiea, Edin. Dubl. gum arabic 
emulsion. 
Emulsio camphorata, Edin. mistura cam- 
phorata, Lond. camphorated emulsion or 
mixture. 
Lac ammoniaci, Lond. Dubl. emulsion of 
gum ammoniac. 
Lac asse faetidae, Lond. emulsion of asa- 
foetida. 
Mistura moschata, Lond. musk mix- 
ture. 
Mistura cretacea, Lond. chalk mixture. 
Decoctum cornu eer.vi, Lond. decoction 
of hartshorn. 
Class XV. Aceta. Medicated Vine- 
gars. 
Infusions of vegetable substances in acetic 
acid are commonly called medicated vine- 
gars. The action of the acid in this case 
may be considered as twofold. 
1 . It acts simply as water, in consequence 
of the great quantity of water which enters 
into its composition, and generally extracts 
every thing which water is capable of ex- 
tracting. 
2. It exerts its own peculiar action as an 
acid. In consequence ot this it'sdmetimes 
increases the solvent power of its watery 
portion, or dissolves substances which water 
alone is incapable of dissolving, and in a 
few instances it impedes the solution of 
substances which water alone would dis- 
solve. 
As acetic acid, in itself sufficiently perish- 
able, has its tendency to decomposition 
commonly increased by the solution of any 
vegetable matter in it, it should never be 
used as a menstruum, unless where it pro- 
motes the solution of the solvend, as in ex- 
tracting the acrid principle of squills, colchi- 
cum, &c. and in dissolving the volatile, 
and especially the empyreumatic oils, or 
where it coincides with the virtues of the 
solvend. 
Acetum aromaticum, Edin. aromatic 
vinegar, thieves vinegar. 
Acetum colchici. Dub. vinegar of mea- 
dow saffron. 
Acetum scilliticum, Lond. acetum scillas 
maritimae, Edin. vinegar of squills. 
Acidum acetosum camphoratum, Edin. 
camphorated acetous acid. 
Class XVI. TinctuTtn, ^’inctures. 
The term tincture has often been em- 
ployed in a very vague sense. It is now 
commonly applied to coloured solutions, 
made by digestion, in alcohol, or diluted 
alcohol. But it is also, though perhaps in- 
correctly, extended to solutions in ether, 
ethereal spirits, and spirit of ammonia. 
Alcohol is capable of dissolving resins, 
gum resins, extractive, tannin, sugar, vola- 
tile oils, soaps, camphor, adipocere, colour- 
ing matters, acids, alkalies, and some com- 
pound salts. Many of these, as the gum re- 
sins, soaps, extractive, tannin, sugar, and 
saline substances, are also soluble in water, 
while water is capable of dissolving sub- 
stances, such as gum, gelatine, and most of 
the compound salts, which are insoluble in 
alcohol. But the insolubility of these sub- 
stances in the different menstrua is not ab- 
solute, but merely relative; for a cer- 
tain proportion of alcohol may be added to 
a solution of gum in water without decom- 
posing it ; and a solution of resin in alcohol 
will bear a certain admixture of water 
without becoming turbid. Therefore, di- 
luted alcohol, which is a mixture of these 
two menstrua, sometimes extracts the vir- 
tues of heterogeneous compounds more 
completely than either of them separately. 
Alcohol is used as a menstruum. 
1. When the solvend is not soluble, or 
sparingly soluble, in water. 
2. When a watery solution of the solvend 
is extremely perishable. 
3. When the use of alcohol is indicated as 
well as that of the solvend. 
In making alcoholic tinctures, we must 
observe, that the virtues of recent vegetable 
matters are very imperfectly extracted by 
spirituous menstrua. They must therefore 
be previously carefully dried, and as we 
cannot assist the solution by means of heat 
we must facilitate it by reducing the solvend 
to a’state of as minute mechanical division as 
possible. To prevent loss, the solution is 
commonly made in a close vessel, and the 
heat applied must be very gentle, lest it be 
broken by the expansion of vapour. 
The action of tinctures on the living sys- 
tem is always compounded of the action of 
the menstruum, and of the matters dis- 
solved in it. Now, these actions may either 
coincide with, or oppose, each other; and 
as alcohol is at all times a powerful agent, it 
is evident that no substance should be exhi- 
bited in tlie form of a tincture, whose 
action is different from that of alcohol, un- 
less it be capable of operating in so small a 
