ON ALCOHOLIC TINCTURES. 
23 
Are these four parts of alcohol sufficient to extract the 
whole of the active principles of the animal or vegetable 
substance employed, or does not a certain quantity of these 
principles remain in the substance, not being able to enter 
into solution in the alcohol, on account of the small quan- 
tity of that vehicle? In the first place the proportion be- 
tween the alcohol and the substance employed would be 
correct ; in the second, this proportion would not be correct; 
and the result of this uncertainty would be that, if the prac- 
titioner should prescribe any particular dose of a tincture, 
he would not know how much of this tincture represented, 
the substance employed in its preparations, how many parts 
it contained of the vegetable or animal matter in the solu- 
tion, and consequently he would not be able to judge with 
certainty of its effects. 
The first, and I should say the only attempts known for 
determining the real strength of the alcohol, as well as the 
proportional quantity to employ in the preparation of tinc- 
tures, were made in 1S17, by Messrs. Cadet and Deslau- 
riers.* 
The process these able pharmacopolists employed, and 
which they have laid down as the best means of arriving at 
results as exact as possible, is divided into two distinct ope- 
rations. 
The first consists in completely exhausting a given weight 
of each substance, previously dried in stove, by maceration 
in cold alcohol at 36° Baume ; the reduction in the weight, 
of this substance indicates the quantity of matter dissolved 
by the alcohol. In performing the same operation with 
distilled water, we obtain the proportions of matter dissolved 
by the water and the alcohol, separately, and we ascer- 
* {Journ. de Pharmacie, Vol 3. p. 402.) I ought, however, to men- 
tion the attemps to attain the same end, made by M. Masson-Fonr, 
(Bulletin de Pharm, Vol. 1,) and those of M. Coldefrey, (Journ de 
Pharm, Vol. 2.) which consisted in exhausting the substances on which 
they operate, by macerating them several times in hot alcohol, &c. , 
but time and practice have proved that the end did not justify the means. 
