ON THE SUBLIMATION OF THE ALKALOIDS. 
11 
liq. aramonise, and only evanescent crystals by dilute hydrochloric acid. Dilute 
chromic acid, or a solution of bichromate of potash, developes characteristic 
crystals, valuable as being distinct from the reactions of the same acid with 
morphine and strychnine. The smallest quantity not specified. 
4. In veratrine we encounter the first alkaloid which yields a crystalline sub¬ 
limate by Helwig’s method. He describes these crystals as rhomboid,—rhom- 
boidal prisms,—and four-sided plates arranged star-shaped ; sometimes as whet¬ 
stone shaped. These crystals are best seen in the thinner sublimates. The 
reactions with distilled water, liq. ammoniae, dilute hydrochloric acid, and 
dilute chromic acid, are not characteristic. The delicacy of the test of subli¬ 
mation is not indicated. The odour of the sublimate is described as highly dis¬ 
agreeable and penetrating. 
5. The sublimate of atropine contains neither crystals nor granules ; and its 
reactions are uncertain and unstable. The vapour has a peculiar sweetish 
odour. 
6. Aconitine also yields a non-crystalline sublimate, and of the reactions only 
that with dilute hydrochloric acid yields crystalline forms. 
7. Solanine yields eminently satisfactory results. The vapours have a most 
agreeable odour, and deposit crystals which are in the single form of needles 
springing from a point, and usually lying across each other as a network. The 
sublimate is so well defined that it alone suffices for the recognition of the alka¬ 
loid. Distilled water, liq. ammoniae, and dilute chromic acid yield no charac¬ 
teristic reactions ; but dilute hydrochloric acid developes crystals after the lapse 
of 24 hours or more. 
8. Dicjitaline , on the other hand, yields no crystalline sublimate; but the 
vapour has the characteristic odour of the drug. The reactions with distilled 
water, liquor ammonise, and dilute chromic acid are of no value; but dilute 
hydrochloric acid, after 24 hours, and with delicate manipulations, appears to 
yield characteristic crystalline results. The other mineral acids also give cha¬ 
racteristic, though delicate, reactions. 
It appears, then, that out of eight alkaloids chosen on account of their im¬ 
portance as poisons, two ( veratrine and solanine ) yield characteristic crystalline 
sublimates, by which they are at once distinguished from the remainder of this 
group, while two others (morphine and strychnine ) in an eminent degree, and 
one ( brucine ) in an inferior degree, yield sublimates which give characteristic 
crystalline forms with reagents. 
These are the first results of a method of procedure which, as I have already 
stated, admits of obvious improvement, and yields, when so improved, crystal¬ 
line sublimates of strychnine and morphine of great beauty, and, as I shall soon 
have occasion to show, of great interest to the micro-chemist and microscopist. 
The short notice of morphine given above is the only one of the eight which 
makes direct mention of the smallest quantity from which a sublimate may be 
obtained. A thousandth of a grain is specified, and it may be inferred from 
the statements made respecting other of the alkaloids (namely, that the quantity 
used will give a succession of five or six sublimates), coupled with the remark 
already cited that the one-hundredth part of a grain is too large to yield clear 
and good results, that sublimates are obtainable from other alkaloids, as well as 
from morphine, by using such quantities as the thousandth of a grain. Now, 
as it is quite obvious that in order to prove the utility of the method of subli¬ 
mation we must begin by demonstrating its delicacy, I lost no time in as¬ 
certaining this point for myself by operating with the alkaloid strychnine. I 
had the one-hundredth of a grain of this substance weighed in a delicate 
balance, and, with common care, obtained fourteen successive sublimates, 
eleven before the change of colour or melting of the alkaloid, and three after¬ 
wards. As the fifteenth sublimate was smoky, it was not reckoned, and the 
