CHEMICAL REACTIONS OF STRYCHNIA. 
415 
tain, and, secondly, if organic matter be present, the colour 
will be masked; and, thirdly, if a nitrate or chloride is with 
the strychnia, the colour is not produced at all; and, 
fourthly, if strychnia be entirely absent, but sugar and bile, 
or piperine, or any of those substances be present which 
give a purple or red reaction with sulphuric acid, a fallacious 
result will be obtained; and lastly, if the result fails, the 
whole of the strychnia is lost, and the inquiry brought to an 
unsatisfactory conclusion. 
So strongly have I felt these difficulties, that in my paper 
on the Medico-legal Chemistry of Strychnia , published in the 
Lancet of June and July, 1856,* I have endeavoured to 
guard the operator against them by describing a process 
which generally ensures success. It is as follows :—“ First, 
place the strychnia, or the suspected matter, on a clean 
white plate; then touch it with a small drop of concentrated 
sulphuric acid (the acid should be free from nitric acid) ; 
stir it about with a glass rod, so as to mix the strychnia 
very perfectly with the acid; allow it to remain in this state 
for a few minutes, and if the strychnia be pure there will be 
no discoloration.t Then cautiously add the reagent, namely, 
peroxide of lead, bichromate of potash, or peroxide of man¬ 
ganese, taking care not to add too much of it; in fact, it is 
best done by dropping the powder into the oil of vitriol and 
strychnia from the point of a penknife. Lastly, either 
incline the plate so that the acid may gently flow over the 
the powder, or else with great caution stir the powder about 
with the point of a glass rod. In this way the colour is 
always sure to be brought out, and, as far as I know, it is 
not to be confounded with the reaction of other substances. 
Indeed, the only thing which approaches it in appearance is 
the dirty violet colour which is occasioned by morphia and 
its salts when they are treated in the same way. As to the 
so-called fallacies to the test, namely, salicine, bile, sugar, 
pyroxanthine, piperine, resinous matters, and many other 
things, it must be manifest that they are not fallacies when 
the test is properly performed, for all these compounds 
acquire their colour directly the sulphuric acid is added to 
them, and before the other reagent is applied. 
£< Of all the substances which have been proposed for thus 
* See ‘Lancet/ June 28, 185G, and July 12, 1856. 
t The process to be followed for rendering the strychnia pure is detailed 
at page 37 of the ‘Lancet’ for July 12, 1856; it consists in treating the 
impure strychnia with concentrated sulphuric acid until all the impurities 
are destroyed and then extracting with chloroform or ether. 
