168 
On TEICHMANN’S BLOOD-CRYSTALS. 
By Wiiu1am Henpry, Esq. 
Havine an impression that the nature of Teichmann’s 
blood-crystals, supposed to be that. of pure hematine or of the 
colouring matter of blood, and hence termed hematin-crystals, 
may not be so generally understood as the subject seems to 
merit ; believing also that but very few individuals amongst 
those whom their production may chiefly interest have 
hitherto undertaken manipulations with respect to them, 
and the subject at large possessing a general microscopical 
value, as well as being of some interest in medical juris- 
prudence, I have deemed it worth while to awaken the 
attention of your readers to it, with the earnest hope of 
inducing some to undertake enlarged experiments, and of 
eliciting additional facts, which may tend to still greater 
utility. 
How much it still exists a desideratum to determine con- 
clusively the character of certain supposed blood-stains can 
only be evinced by the recent contributions to scientific 
journals and in various other publications, mostly relating to 
some modifications of the usual chemical measures applicable 
to the question (‘Chemical News,’ June, 1861) as contained 
in an article by Guibourt, also (idem, November, 1861) 
another on the subject by Thomas D. Toase, of Jamaica, 
who quotes Fowne, Miller, and Taylor; but if we refer on 
the other hand to Kolliker (edit. 1860, p. 526), and also to 
Virchow, translated by F. Chance (1860, p. 145), we find 
therein a value put upon Teichmann’s crystals by these 
authors, as also by Briicke and others, perhaps not hitherto 
sufficiently regarded by the leading authorities in our own 
country. ; 
Now I think, in all justice, the subject is well worthy of 
every consideration, for satisfactory as may be the ordinary 
chemical means of determining the nature of supposed blood- 
stains or spots, as taught by Taylor and others, consisting in 
steeping, boiling, the application of ammonia, the production 
of a coagulum or precipitate, then filtering, drying, boiling in 
caustic potash, and the further productions of solubility and 
colour, occasions still may arise when in the case of stains or 
spots of very minute size, or occurring under various circum- 
stances, the production of Teichmann’s crystals might afford 
the most available and conclusive evidence in the matter. 
