GLOBULIN. 1035 



mass afterwards diluted with distilled water, and allowed to 

 settle. The liquid above was perfectly clear and colourless, 

 and contained sulphate of iron. The insoluble blood-mass was 

 washed on a filter with water, so long as the washings con- 

 tained iron. Boiled afterwards in alcohol, the mass coloured 

 the spirit intensely red. On neutralising the sulphate of the 

 colouring matter, the compound in solution, with ammonia, 

 much albumen fell, which was dried and ignited ; it left a white 

 ash, in which not a trace of iron could be detected. The blood 

 red solution in alcohol therefore contained no iron. 



GLOBULIN. 



This substance is the principal constituent of the blood glo- 

 bules ; it is a protein compound and closely allied to albumen. 

 But it has not been isolated, and little is known respecting it. 

 The sulphate of globulin which remains behind in the prepara- 

 tion of hematosin, described above, consists of 4 atoms of pro- 

 tein, united with 1 atom of sulphuric acid. The nature of the 

 matter forming the clear nucleus of the globules is still less under- 

 stood, but it appears more like coagulated fibrin than anything 

 else. 



The matter of the blood globules, or the globulin and hema- 

 tosin together, may be obtained by mixing blood freed from 

 fibrin, with a solution of sulphate of soda, in which the matter 

 of the globules is insoluble and precipitates ; or by draining the 

 serum out of the clot of blood cut into thin slices, upon folds of 

 blotting paper, and afterwards mixing the clot with water, in 

 which the matter of the blood globules dissolves of a brown-red 

 colour and transparent. It is soluble in pure water, insoluble 

 in serum. When its solution is mixed with salts of an alkaline 

 base or with sugar, and exposed to air, it becomes of a lively 

 red. The solution of the matter of the blood globules may be 

 evaporated at 1 22 without losing its solubility ; but when heated 

 it coagulates, before its temperature rises to 181, and precipi- 

 tates insoluble. Both in its coagulated and soluble state the 

 matter of the blood globules exhibits similar effects with reagents 

 as albumen in the same conditions. M. Simon has lately main- 

 tained that this matter is composed of casein and hematosin, 

 but coagulation by heat is not a "property of casein. 



