158 Society for Experimental Biology and Medicine. 



monium hydrate, sodium hydrate, magnesium hydrate, calcium 

 hydrate and barium hydrate; salts — sodium carbonate; mag- 

 nesium sulphate, phosphate, acetate and carbonate ; calcium sul- 

 phate, nitrate, phosphate, acetate, oxalate and carbonate ; barium 

 sulphate, phosphate and carbonate. Urea was also included. 



It was found that all acids and alkalies are able to inactivate 

 complements when used in sufficient concentrations. With mono- 

 basic acids it takes about I c.c. of 72/40 solution to inactivate 1 c.c. 

 of active serum. About 1 c.c. of 72/50 solution of the acid is, as 

 a rule, neutralized by the inherent alkalinity of the serum. 



With alkalies 0.3 c.c. (ammonium hydrate 0.8 c.c.) is sufficient 

 for inactivation. The acids and alkalies are, when used without 

 serum, hemolytic in the quantities stated. But when mixed with the 

 serum they — serum and chemicals — lose their activity mutually. 



Alkaline salts of strong acids are not anti-complementary 

 unless a certain limit of concentration is exceeded. Sodium car- 

 bonate is anti-complementary in a relative, but not in an absolute 

 sense. All other salts employed are strongly anti-complementary, 

 the magnesium salts being the least inhibiting. Calcium and 

 barium salts of strong acids are absolute anti-complements, while 

 the carbonates of these elements may or may not be active upon 

 complements. 



Complements which are inactivated by acids can be reacti- 

 vated by neutralizing the acids with alkalies, and vice versa. The 

 action of various acids, alkalies and salts upon complements renders 

 the complement-deviation phenomenon for forensic purposes less 

 safe, because the materials are often impure in practical cases. 



Various soluble salts of oleic acid are accelerators of the com- 

 plementary action of serum. 



