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268 ON THE EXTRACT OF RHATANY. 
position and medicinal activity, viz. : 1st. By alcohol. 2d. 
By diluted alcohol. 3d. By decoction in water. 4th. By 
infusion in warm water: and lastly; by displacement with 
cold water. 
1st. Rhatany, when treated* with alcohol of 33° Baume, 
yields a larger amount of extract than by any other means; 
but it is the least soluble, and hence Soubeiran has suggested 
that it should be banished from the list of therapeutic agents. 
2d. The Codex of 1818 directs this extract to be made 
with alcohol of 22° Baume, or diluted alcohol. By this treat- 
ment the root yields a large product, but the menstruum takes 
up a quantity of inert apotheme, and to this extent the re- 
medy is reduced in power. This mode of preparing the ex- 
tract has been much employed in France, and it is to be pre- 
ferred to the boiling process. 
3d. The next form of extract is that obtained by boiling 
the root in water, which is the least to be recommended of 
all the modes of treating rhatany. Not only is the tempera- 
ture of boiling water injurious, but also in proportion to its con- 
tinuance. According to Boullay,t when treated by imme- 
diate displacement with boiling water, until four parts of 
fluid have passed, rhatany yields nearly one-fifth of its 
weight of dry extract; one-half of which is soluble in cold 
water. 
If, on the contrary, one part of rhatany is boiled in four 
parts of water, then thrown on a displacement filter and suf- 
fered to drain, and afterwards enough boiling water added to 
make four parts of the decoction, the product in dry extract 
is only one-sixth of the root employed, not one-half of which 
is soluble. By repeating the decoction with as much boiling 
water, about half as much more extract was obtained, less 
soluble than the preceding. Thus, by two successive decoc- 
tions, one pound of rhatany yielded thirty-one drachms of 
extract, containing only twelve and a half drachms of soluble 
matter. 
*Guibourt, Pharm. Raisonee, 
f Essay on Displacement. 
