On the Coagulation of the Blood. 



259 



and which, moreover, is rendered inactive at the temperature at 

 which fibrin ferment, as ordinarily prepared from serum, loses its 

 activity. 



The next question which I investigated was whether the ferment 

 action was dependent upon, or independent of, the presence of the 

 proteids of the cells. An extract of the cells was made with sodium 

 sulphate solution, and saturated with ammonium sulphate ; the pre- 

 cipitate of the proteids so produced was filtered off ; the proteid-free 

 filtrate dialysed till free from excess of salt,* and it was then found 

 to have no power of hastening coagulation. The precipitate which 

 contained all the proteids was washed by saturated solution of ammo- 

 nium sulphate, and redissolved by adding distilled water (Solution A) ; 

 this solution hastened the coagulation of salted plasma very con- 

 siderably. This experiment showed either that the ferment was 

 identical with or precipitated with the proteids in the extract. It 

 was. moreover, destroyed at a temperature at which these proteids 

 were coagulated, viz., about 75° C. ; there are, however, in Solution A 

 two proteids which are coagulated at about this temperature, viz., 

 the cell globulin and the cell albumin. These were separated by 

 saturating the solution with magnesium sulphate ; the globulin was 

 precipitated, washed, and redissolved by adding water (Solution B). 

 The filtrate from this precipitate was dialysed till free from salt 

 (Solution C). Solution B was dialysed until nearly free from salt, 

 but not sufficiently free to cause precipitation of the globulin ; it was 

 divided into two equal parts, B' and B" ; B' underwent no further 

 treatment. B" was dialysed till the globulin was precipitated ; the 

 globulin was then filtered off, washed with distilled water, the pre- 

 cipitate dissolved in 0*3 per cent, sodium chloride solution (Solu- 

 tion D). The solution B" minus the globulin precipitated by dialysis 

 still contained a small quantity of globulin ; this may be called 

 Solution E. 



The influence of each of these solutions on dilute salted plasma was 

 then investigated. The results may be summarised as follows : — 



Solution C (containing only cell albumin) did not hasten the coagu- 

 lation of salted plasma, but in some cases even caused delay. 



Solution B' (containing only cell globulin) hastened very considera- 

 bly the coagulation of such plasma. 



Solution E (containing very little cell globulin) hastened the coagu- 

 lation to a slight extent. 



Solution B (containing the cell globulin precipitated from Solu- 

 tion B by dialysis) hastened the coagulation considerably. 



These experiments show that it is not the albumin but the globnlin 



* This experiment, and the others in which dialysis was employed, were carried 

 out in the cold winter months, and thymol was always added to prevent putre- 

 faction. 



