490 APPENDIX. 



observed by O. Funke,* were prepared exclusively for microscopical 

 examination by him and by F. Kunde,f to whom we owe the dis- 

 covery of the tetrahedric and the hexagonal blood-crystals; the 

 method they employed was, to cover a minute drop of blood with 

 a glass slide, and after a small quantity of water, alcohol, or ether 

 had been poured upon it, the whole was exposed to gradual 

 evaporation. I have now succeeded, J by different methods, in 

 exhibiting these crystals on a large scale and with tolerable quick- 

 ness, and in all these modes of preparation light and atmospheric 

 influences constitute the most essential conditions towards the 

 rapid formation of these crystals. The method of preparation 

 frequently requires to be very considerably modified in different 

 kinds of blood. Funke has shewn, in his careful experiments on 

 the mode of formation of these crystals under a glass slide, that it 

 is essentially necessary that the blood-cells should first burst 

 before crystallisation can begin, and the only available means are 

 water, alcohol, and ether, as has been shown by Funke and 

 Kunde. The evaporation which occurs after the formation of the 

 crystals under a glass slide, is by no means so important as it 

 would appear, since, for instance, the blood (of guinea-pigs) may be 

 diluted with twice its volume of water, and yet the crystals may 

 be perfectly separated in the course of three-quarters of an hour 

 after the employment of a proper method of treatment ; in other 

 soluble crystals, as, for instance, in those of the dog, it is necessary 

 to facilitate their separation by the addition of an adequate amount 

 of alcohol. 



Tests. Although this substance differs so essentially from all 

 other protein-bodies by its capacity for crystallisation, its in- 

 different behaviour towards moderately diluted hydrochloric and 

 sulphuric acids, towards nitrate of silver, neutral and basic acetate 

 of lead, bichloride of mercury, &c., it is extremely difficult and 

 sometimes even impossible to recognise it, when it is present only 

 in small quantities, or when it is mixed with many other protein- 

 substances. Since other protein-bodies or their immediate pro- 

 ducts of metamorphosis share at least in some of the properties which 

 appertain to it, its presence in a mixture of protein-substances, 

 could not be regarded as thoroughly proved, until its crystals had 



* Dissert, inaug. Lips. 1851 ; and Zeitschr. f. rat. Med. N. F. Bd. 1, S. 

 814-192, Bd. 2, S. 199-244, u. 288-292. 



j- Zeitschr. f. rat. Med. N. F. Bd. 2, S. 271-287. 



% Ber. d. k. sachs. Ges. d. Wiss. 1852, S. 23-26, u. 78-84. 



