ON THE ADULTERATION OF DRUGS. 123 
not noticed in any work on pharmacy I have seen, — in 
consequence of having lately made a detailed inquiry into the 
sources and composition of the different kinds of gamboge, 
which has been published in the Companion to the Botanical 
Magazine. Three kinds of the drug are known in the Eng- 
lish market, which all come from Siam by way of Singapore, 
namely, pipe, lump, and coarse gamboge. The first is per- 
fectly pure, consisting of resin, gum, and a little moisture; 
and the resin, its active part, amounts on an average to seventy- 
three per cent. The two others, which a person of skill can 
easily distinguish in mass, but not so easily in powder, are 
invariably adulterated. The impurity is probably some com- 
pound amylaceous matter, for there is both fecula and lignin; 
and, for reasons I need not stop to explain, it must be intro- 
duced intentionally. The amount in lump gamboge is about 
eleven per cent., probably too little to affect appreciably its 
medicinal activity. But in the coarse gamboge, — which some 
class with the lump variety, and with reason, since its com- 
position is the same in kind, — the proportion of impurity is 
much greater. I have found in one specimen twenty-three 
per cent, of fecula, lignin, and moisture together; and in 
another so much as 51.5 per cent. In the latter the active 
resin amounted to no more than thirty-five per cent, or less 
than one-half the due proportion. It cannot be doubted that 
any one, who should take the same dose of such a sample one 
day, and of the pure variety the next, would find very good 
cause to complain of the precarious action of gamboge. 
7. Few articles of the Materia Medica present a history 
more full of interest than scammony. Known and described 
by Dioscorides about two thousand years ago, it has been 
handed down from century to century, through an almost 
unbroken series of physicians and authors, even to the present 
time. The descriptions of those who speak from actual ob- 
servation, correspond on the whole closely with the characters 
of the modern drug; but which is of more consequence to us, 
all complain of its frequent adulteration; and singularly 
