36 OTHER CONSTITUENTS OF RED CORPUSCLES. 



In cases where a large amount of blood has undergone solution 

 within the blood-vessels (as by injecting foreign blood), hsematoidin 

 crystals have been found in the urine (v. Kecklinghausen, Landois). 



21. (B.) The Colourless Proteid of Haemoglobin. 



It is closely related to globulin ; but, while the latter is precipitated 

 by all acids, even by C0 2 , and re-dissolved on passing O through it, 

 the proteid of haemoglobin, on the other hand, is not dissolved after 

 precipitation on passing through it a stream of 0. 



As crystals of haemoglobin can be decolourised under special circumstances, it 

 is probable that these owe their crystalline form to the proteid which they 

 contain. Landois placed crystals of haemoglobin along with alcohol in a dialyser, 

 putting ether acidulated with sulphuric acid outside, and thereby obtained 

 colourless crystals. [If frog's blood be sealed up on a microscopic slide, along 

 with a few drops of water for several days, long colourless acicular crystals are 

 developed in it (Stirling and Brito).] 



22. II. Proteids of the Stroma. 



Dry red human blood-corpuscles contain from 5*10-1 2*24 per cent, 

 of these proteids, but little is known about them (Jiidell). One of 

 them is globulin, which is combined with a body resembling nuclein 

 (Wooldridge), and traces of a d'iastatic ferment (v. Wittich). Tho 

 stroma tends to form masses which resemble fibrin (Landois). 



L. Brunton found a body resembling mucin in the nuclei of red blood- corpuscles, 

 and Miescher detected nuclein. 



23. The Other Constituents of Red Blood-Corpuscles. 



III. LECITHIN (Q-35-0'72 per cent.) in dry blood-corpuscles (Jiidell), 

 and also in brain, yelk, and seminal fluid. 



It is regarded as a glycero-phosphate of neurin, in which, in the radical of 

 glycero-phosphoric acid, two atoms of H are replaced by two of the radical of 

 stearic acid. By gentle heat glycero-phosphoric acid is split up into glycerine and 

 phosphoric acid. 



CHOLESTERIN (0*25 per cent.); no FATS. 



These substances are obtained by extracting stromata or blood itself with ether. 

 When the ether evaporates^ the characteristic globular forms (" myelin-forms ") of 

 lecithin and crystals of cholesterin are recognised. The amount of lecithin may 

 be determined from the amount of phosphorus in the ethereal extract. 



IV. WATER (681-63 per 1,000 C. Schmidt). 



V. SALTS (7'28 per 1,000, C. Schmidt), chiefly compounds of 



