718 
ON THE SUBLIMATION OF THE ALKALOIDS. 
compounds. Its primary form is a hexagonal prism, and it is obtained in this 
condition if crystallized slowly in a tube from its alcoholic solution. But if a 
warm alcoholic solution be allowed to evaporate on a slip of glass, it takes the 
shape of very thin hexagonal plates, the minute crystals resembling uric-acid 
lozenges. I send you a sketch, drawn accurately, X 150 diameters. The nitrate, 
sulphate, hydrochlorate, and acetate are much more difficult to determine the 
forms of. I have only obtained them as bundles of minute needles, even with 
high powers I cannot make out anything more. They mostly are packed into 
masses so closely as to appear merely striated with fibrous brush-like ends. Oc¬ 
casionally they may be seen in stellate groups. The hydrochlorate, which you 
sent on glass,* is of this stellate form, but the characters of the individual 
crystals are undeterminable. 
“ I could have wished to have sent you more positive details and fuller, con¬ 
cerning this interesting substance, but it is satisfactor}^ at least to find that in 
one of its characteristic forms it might be identified amongst the other opium 
alkaloids by means of the microscope.” 
ON THE SUBLIMATION OF THE ALKALOIDS. 
BY WILLIAM A. GUY, M.B., F.E.S., F.K.C.r,, 
PROPESSOR OP POEENSIC MEDICINE, KING’s COLLEGE, LONDON, ETC. 
I. 
In the year 1864, Dr. A. Ilelwig, of Mayence, first proposed the sublimation 
* The crystals, here referred to by Mr. Brady, were a portion of what we have inferred, in 
