196 
ON THE SUBLIMATION OF THE ALKALOIDS. 
lopes ; and, on submitting one of them to heat, I obtained five successive subli¬ 
mates, of which three were amorphous, with the usual fringed border, and two 
showed a crystalline formation chiefly in the shape of lattice-work. The rest 
of the deposits yielded one, two, or three sublimates each. 
By the first of these procedures it will be observed that I obtained five 
deposits , containing, on the average, ^u-th of a grain of strychnine, and by the 
second five sublimates , each consisting of the same small quantity of the alkaloid, 
—the s o^ pth of a grain. The two groups also resembled each other in presenting 
continuous white circular stains, the first with bright crystalloids, the second 
with crystalline formations at the margin or in the body of the spot. I accord¬ 
ingly availed myself of the opportunity which this agreement in number and 
quantity afforded to put to the test of comparison the deposit and the sublimate. 
The following were the results which I obtained:— 
The colour-test. —I treated the two spots in precisely the same way, first dis¬ 
solving them in a drop of sulphuric acid, and then adding a very minute frag¬ 
ment of the bichromate of potash. The deposit underwent no change of colour ; 
the sublimate took on the characteristic rich blue tint, and underwent the usual 
change through mulberry to light red. A second experiment gave exactly 
the same results : with the deposit no change; with the sublimate a perfectly 
characteristic development and change of colour. 
Solution of Bichromate of Potash ( T ^)-—Instantaneous formation of groups 
of needles projecting into the liquid, and of square and oblong plates detached 
and grouped, with a few fragments of scum, in the case of the sublimate ; in 
the case of the deposit , large quantities of floating scum (the material of a dense 
precipitate), partial solution of the crystalloids, but no formation of defined 
crystals. 
Solution of Carbazotic Acid (^o).—With sublimate , immediate formation of 
greenish-yellow spots, and rapid development of beautifully characteristic groups 
of hooked crystals; with deposit , quick formation over the whole surface of 
groups of needles, some of large size, with here and there distinct small groups 
of hooked crystals, and at the margin the crystalloids fringed with small short 
needles. Second experiment with the same solution:—The sublimate (small, and 
probably containing much less than the ten-thousandth of a grain) showed the 
same instantaneous development of spots and crystals ; while no immediate 
effect took place with the larger deposit, but, after some minutes, small groups 
of hooked crystals showed themselves. 
From these comparative experiments, of which the results are in accordance 
with my previous experience, I infer that sublimates of strychnine yield better 
results than direct deposits from solutions ; that they may respond to the colour- 
tests when the deposits fail; and that their reactions are much more certain, 
delicate, and characteristic. I am inclined to attribute this superiority of subli¬ 
mate to deposit to greater delicacy of structure. The sublimate, as it forms, 
may be seen to spread over the surface of the glass disk as a milk-white layer 
of nearly uniform thickness, and if crystals do not form on its surface or at its 
margin, they are as a general rule delicate and well defined; but deposits from 
a solution are apt to gather themselves into crystalloids at the margin, and into 
large ill-shaped crystalline masses on the surface. 
Of the reaction with carbaz otic acid test I shall "have an early opportunity of 
speaking more in detail; but, if lam not greatly mistaken, it will prove the most 
certain, delicate, and characteristic test for strychnine, especially when it is applied 
to the sublimates of that alkaloid. Meanwhile, it is a fact of the utmost interest 
and practical importance, that in two instances at least, sublimates consisting 
of not more than -g-duis °f a grain have responded to the colour-test, when two 
deposits of equal weight have failed to do so. 
It must be borne in mind that these experiments with strychnine are here 
