430 
COLOUR-TESTS FOR STRYCHNIA, ETC. 
alkaloids and active principles, whether coloured or colour¬ 
less, which yield colours when treated with sulphuric acid 
alone. Of those which resemble strychnia in giving no 
colour with sulphuric acid, it may be stated with equal con¬ 
fidence, that not one of them yields with the colour-deve¬ 
loping substances the true strychnia colours, or any colours 
resembling them. 
The foregoing are given as examples of the sort of ob¬ 
jections that are urged against the colour-tests for strychnia. 
They belong to the class of objections which no one out of a 
court of law would bring forward as worthy of serious atten¬ 
tion. They are based, not so much on a misapprehension of 
the facts, as on an illogical comparison of dissimilar phe¬ 
nomena. But there is one objection founded on a misap- • 
prehension and quite unintentional misrepresentation, which 
ought not to be passed over in silence. It is stated by 
Dr. Taylor, in his work on Poisons, that the alkaloid curarina 
obtained from the South American poison curara resembles 
strychnia in the action of the colour-tests, brucia in the 
action of nitric acid, and both in its intense bitterness. 55 
These are the words used by Dr. Taylor, at p. 786 of the 
second edition of his work; and on referring to p. 772, he 
says of the same alkaloid, that “ strong nitric acid produces 
with it a blood-red colour; sulphuric acid gives with it a rich 
carmine tint, in which characters it resembles brucia, 55 and 
further that Pelikan found pure curarina to possess the 
chemical properties of strychnia, so far as the colour-tests are 
concerned, and with more constant results. Thus sulphuric 
acid when conjoined with the action of chromate of potash, 
ferricyanide of potassium, or peroxide of lead, “ produced a 
beautiful play of colours/ 5 and that “ the galvanic test acted 
similarly. 55 Now, on referring to the passage cited from 
Pelikan, I find that this beautiful play of colours is a trans¬ 
lation of the words ic des colorations rouges tres belles, 55 and 
“ la coloration rouge, 55 the one expression being applied to 
the chemical tests, the other to the galvanic test. So that 
the alkaloid curarina is set up as a fallacy on the strength of 
its yielding with the colour-tests (sulphuric acid mixed with 
chromate of potash, ferricyanide of potassium, or peroxide of 
lead) a brilliant red colour, or colours, instead of the beautiful 
play of colours, blue, mulberry, and red, which jointly, and 
not separately, characterise strychnia. If any one colour is 
to be deemed the strychnia colour par excellence, it is the 
rich, deep blue, and not the brilliant red. Let it also be 
remembered that sulphuric acid gives with curarina, according 
to Bernard, a rich carmine tint, while strychnia undergoes no 
