374 Proceedings of Royal Society of Edinburgh. [sess. 
it in Table II. It is possible still more to lower the coagulation 
point by the addition of larger quantities of the latter salts, until 
one can precipitate the albumen by double saturation at the tempera- 
ture of the laboratory. On the other hand, the addition of large 
quantities of NaCI and Na 2 S0 4 exerts very little action. 
Effect of Magnesium Sulphate on the Coagulation Point of Serum 
Albumen. 
Although Dr Halliburton has succeeded (Reference 6, p. 192) in 
precipitating serum albumen by double saturation by means of 
sulphate of magnesium in conjunction with such salts as sodium 
sulphate, sodium nitrate, potassium iodide, &c., magnesium sulphate 
in itself raises the coagulation point of serum albumen. 
(a) Serum albumen, containing 100 per cent, magnesium sulphate, 
became opalescent at 84° C., and coagulated at 89° C., a slight 
opalescence appearing at 40° C., due to a trace of serum globulin. 
( b ) Serum albumen, containing 50 per cent, magnesium sulphate, 
became opalescent at 77° C., and coagulated at 86° C. 
(c) Serum albumen, containing 25 per cent, magnesium sulphate, 
became opalescent at 76° C., and coagulated at 84° ‘75 C. 
(ft) Serum albumen, containing 12 \ per cent, magnesium sulphate, 
became opalescent at 76° C., and coagulated at 82° C. 
(e) Serum albumen, containing 6J per cent, magnesium sulphate, 
became opalescent at 74° C., and coagulated at 78° *25 C. 
(/) Serum albumen, containing 3J per cent, magnesium sulphate, 
became opalescent at 72° C., and coagulated at 76° C. 
(g) Serum albumen, somewhat diluted in this experiment, became 
opalescent at 68° C., and coagulated at 75° C., without the formation 
of well-marked flocculi. 
Sodium Chloride. — Although Hoppe-Seyler states that this salt 
lowers the coagulation point of serum albumen, we find that this 
is only the case when present in large quantity. Small quantities 
appear, if anything, to raise it. 
A saturated solution of the same serum albumen as that used for 
the last experiment coagulated at 72° C., when saturated with 
common salt. A solution, containing 20 per cent., became opalescent 
at 74° C., and coagulated at 80°*5 C. 
