368 Proceedings of Royal Society of Edinburgh. [sess. 
per cent, watery solution of magnesium sulphate, coagulated at 
75° C. 
(c) When diluted with two volumes, coagulated at 75° ‘5 C. 
(d) When diluted with three volumes, it coagulated at 75° *5 C. 
(e) When diluted with four volumes, it coagulated at 76°-25 C. 
(/) When diluted with five volumes, it coagulated at 77° C. 
(y) When diluted with six volumes, it coagulated at 77° C. 
In another experiment serum globulin was prepared by passing 
a stream of carbon dioxide through dilute blood serum. The pre- 
cipitated globulin was dissolved in 5 per cent, solution of sodium 
chloride. The solution of globulin not being of the same strength 
(a little weaker), and the salt used for its solution being a different 
one, the coagulation points do not correspond with those obtained 
in the previous experiment. 
(a) Serum albumen, dissolved in 5 per cent, solution of sodium 
chloride, became opalescent at 74° C., and coagulated at 79° C. 
(b) Serum albumen, dissolved in 5 per cent, solution of sodium 
chloride and diluted with one volume of a 5 per cent, watery 
solution of sodium chloride, became opalescent at 77° *5 C., and 
coagulated at 81° *5 C. 
(c) Diluted with two volumes, opalescence commenced at 
78°*5 C., and it coagulated at 82° -5 C. 
(i d ) Diluted with three volumes, opalescence commenced at 79° C., 
and coagulated at 84° C. The albumen at this stage had begun to 
putrefy, and on repeating the experiments it was found that the 
coagulation point was raised about two degrees for (a), ( b ), (c), and 
that ( d ) did not coagulate even on boiling. 
The Effect of Dilution on the Coagulation Point of Hydrocele Fluid. 
Hydrocele fluid contains the same proteids as are found in blood 
plasma, namely, fibrinogen, serum globulin, and serum albumen. In 
a case of chronic hydrocele there may be an almost entire absence 
of proteid matter. The proteid substance when present varies in 
amount, and the coagulation point varies with it. On diluting 
hydrocele fluid the coagulation point is raised. 
(a) Hydrocele fluid became opalescent at 65° C.; at 72° C. it 
assumed the consistence of a thin jelly which thickened, and at 
76° C. flocculi separated out. 
