STEWART ON PHARMACOPOEIA. 
31 
Thus an amount of tincture can be obtained equal to the 
spirit used in its preparation. This will be considered quite 
a desideratum in the preparation of the vinum rad. colchici of 
the United States Pharmacopoeia, where the proportion of 
root ordered is so great, that nearly all the wine is absorbed; 
but in adapting the process to this, and some other prepara- 
tions, I would recommend that the water used in displacing 
should be charged with about one-fifth its measure of alcohol, 
in order to prevent it from reviving the mucilage with which 
the root abounds. 
Decoctum Sarsapctrillse Comp. The officinal formula for 
this preparation is a very imperfect one, as the product is 
always charged with inert oxidised extractive matter and fe- 
cula to such a degree that it is impossible for any one to use 
it for any length of time, if at all. While conversing upon 
this subject, about two years since, with one of our most emi- 
nent medical men, and comparing the value of the several pre- 
parations of sarsaparilla, I was struck with the decided prefer- 
ence he gave to the diet drink, if it could be prepared in the form 
of ptisan, and determined to apply the principles of the above 
process to its preparation. My success was far beyond my 
anticipations, as the result was a concentrated solution of all 
that is valuable in the ingredients, free from fecula, and the 
extractive matter is apparently free from the disposition to oxi- 
dise, as it could be reduced to a soluble extract. As I com- 
municated my ideas upon this subject to one of our most skil- 
ful pharmaceutists at the time, and the experience of two 
years has confirmed our impressions as to the superiority of 
this process, I will give it in detail, and refer to an article 
which has since appeared in the American Journal of Phar- 
macy, Vol. X. page 10, where a number of experiments are 
recorded, confirming the above statement. 
I am in the habit of using a small tin funnel, the bowl of 
which does not exceed four inches in diameter, to which is 
soldered a cylinder or cone of tin, eleven inches long, and 
five and a half inches wide at the top — into the neck of this 
is introduced a small willow cap, such as generally cover the 
