378 Proceedings of Royal Society of Edinburgh. [sess. 
(d) Serum globulin, dissolved in a solution containing 12*5 per 
cent, of magnesium sulphate, became opalescent at 7 7° *5 C., and 
coagulated at 80° C. 
(e) Serum globulin, dissolved in a solution containing 6*25 per 
cent, of magnesium sulphate, became opalescent at 76° C., and 
coagulated at 78° *75 C. 
(/) Serum globulin, dissolved in a solution containing 3*125 
per cent, magnesium sulphate, became opalescent at 71° *5 C., and 
coagulated at 77° C. 
Effect of Sodium Chloride on the Coagulation Point of Serum 
Globulin. 
(a) Serum globulin, saturated with sodium chloride, is pre- 
cipitated in the cold. 
(b) Serum globulin, containing 20 per cent, sodium chloride, 
became opalescent at 77° C., and coagulated at 79° *5 C. 
( c ) Serum globulin, containing 10 per cent, sodium chloride, 
became opalescent at 79° C., and coagulated at 81° C. 
(d) Serum globulin, containing 5 per cent, sodium chloride, 
became opalescent at 79° C., and coagulated at 81°*75 C. 
(e) Serum globulin, containing 2*5 per cent, sodium chloride, 
became opalescent at 78° C., and coagulated at 80° C. 
(/) Serum globulin in much smaller quantity does not dissolve 
to form a clear solution. 
Tentative Conclusions regarding the Action of Salts. 
(1) A salt may raise the temperature of coagulation if present 
in a certain percentage ; at another percentage it may lower it. 
Thus common salt raises the coagulation points of both vitellin 
and serum globulin when present in moderately small quantity. 
Large quantities lower the coagulation point. 
(2) If a proteid be present in a saturated solution of a salt — 
such as magnesium sulphate — and, if another salt be then added, 
which by itself would raise the coagulation point, the coagu- 
lation point may in this case be lowered. It appears, too, that 
salts which are most active in raising the coagulation point are most 
active in lowering it, when added to a solution already saturated by 
another salt. 
