28 THE COLOURLESS PROTEID OF HEMOGLOBIN. 



by impure nitric acid (Gmelin's reaction), it gives the same play of colours as 

 bile.] 



Pathological. 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. 

 For their occurrence in the urine in jaundice ( 180), and in the sputum ( 138). 



21. (B.) THE COLOURLESS PROTEID OF HAEMOGLOBIN. It is closely 

 related to globulin ; but, while the latter is precipitated by all acids, even by CO.,, 

 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 O. 



As crystals of hemoglobin can be decolorised under special circumstances, it is probable that 

 thefe owe their crystalline form to the proteid which they contain. Landois placed crystals' of 

 hemoglobin along" with alcohol in a dialyser, putting ether acidulated with sulphuric acid out- 

 side, and thereby obtained colourless crystals. [If frogs' 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. IT- PROTEIDS OF THE STROMA. Dry red human blood-corpuscles con- 

 tain from 510 1224 per cent, of these proteids, but little is known about them 

 (JiideU). One of them is globulin, w r hich is combined with a body resembling 

 nuclein ( Wooldridr/c), and traces of a diastatic ferment (v. Wittich). The stroma 

 tends to form masses which resemble fibrin. 



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

 Mieseher detected nuclein ($ 250, 2). 



23. OTHER CONSTITUENTS OF RED BLOOD-CORPUSCLES III. Lecithin 



(0-35-0-72 per cent.) in dry blood-corpuscles ( 250, 2). Cholesterin (0-25 per 

 cent.) ( 250, III.), no Fats. 



Lecithin is regarded as a glycerophosphate 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 ( 250). 



These substances are obtained by extracting old stromata or isolated blood-corpuscles 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 1000 C. Schmidt). 



V. Salts (7 # 28 per 1000), chiefly compounds of potash and phosphoric acid; the 

 phosphoric acid is derived only from the burned lecithin ; while the greater part of 

 the sulphuric acid is derived from the burning of the haemoglobin in the analysis. 



Analysis of Blood. 1000 parts, by weight, of horse's blood contain : 



344*18 blood-corpuscles (containing about 128 per cent, of solids). 

 655*82 plasma (containing about 10 per cent, of solids). 

 1000 parts, by weight, of moist blood-corpuscles contain : 



Solids, , 367-9 (pig); 400-1 (ox). 



Water, . . . . 632 '1 599 9 

 The solids are : 



. ,. PiK. Ox. 



Hsemoglobin, 261 280*5 



Proteids, 86-1 107 



Lecithin, Cholesterin, and other Organic Bodies, 12 7 5 



Inorganic salts, 8 9 4-8 



( Potash, 5.543 o-747 



Magnesia, 0*158 0*017 



Including \ Chlorine, 1-504 1635 



I Phosphoric Acid, .... 2067 0*703 



LSoda, 2-093 (Bwtge). 



[An approximate estimate of the composition of human blood is given in the 

 following table : 



