44 CHEMICAL CONSTITUENTS OF BODY AND FOOD. 
precipitated is filtered off. The filtrate is allowed to stand at the 
temperature of the air, and as it gets concentrated minute spheroidal 
globules of varying size, and finally minute needles, either aggregated or 
separate, make then- appearance (Fig. 9). On examining these crystals, 
they are found to consist of egg albumin, with a variable (but usually 
small) admixture of ammonium sulphate. Serum albumin has similarly 
been obtained by Giirber and Michel,* in a crystalline form, from the 
blood serum of horses and rabbits. More recently still, caseinogen lias 
been crystallised. When a solution of this substance is mixed with 
Fig 9.— Crystals of egg albumin. 
ammoniacal magnesia mixture, it proceeds after some days to deposit 
sphaeroliths, and ultimately aggregations of needle-like crystals. They 
contain 45 per cent, of ash, and 14 - 98 per cent, of nitrogen. Nuclein 
also yields a crystalline deposit with ammoniacal magnesia mixture 
( v. Moraczewski). 2 
Byrom Bramwell and Noel Paton 3 have described a case of album- 
1 Sitxiiiujib. d. phys.-med. Gcsrlhch. zv. Wurzburg, 1894. Michel {ibid., No. 3, B<1. 
xxix.; Centralbl.f. d. med. Jl'isxensch., Berlin, 1896, S. 152) gives full details of the method 
employed. The crystals are hexagonal prisms with the following percentage composi- 
tion :— C, 53-1 ; H. 7-1 ; N, 15*9 ; S, 1*9 ; 0, 22"0 ; ash. only 0"22. They coagulate at 
51° -53° C. («) D = -61°. 
2 Ztschr. f. physiol. Chem., Strasshurg, Bd. xxi. S. 71. 
3 Eej). Lab. Roy. Coll. Phys., Edinburgh, 1892, vol. iv. p. 47. 
