Scientific Proceedings. ( l 97) 2 7 



0.5 per cent., and a preservative is used. The strength of the fil- 

 tered product is ascertained. It is tested bacteriologically, injected 

 into animals and finally actually administered in the Department of 

 Health hospitals before distributing. 



By this method almost all the ammonium sulfate is removed 

 before dialysis, and the additional acid precipitation gives a purer 

 product. Dialysis is quicker under these circumstances than when 

 the sulfate alone is employed to effect precipitation. The antitoxin 

 is practically all recovered, and a concentration of several times the 

 original potency is easily and constantly obtained. The sodium 

 chlorid separation is sharp, the two groups of proteins showing 

 essentially different physical characters as precipitates. The final 

 product is somewhat viscous, faintly opalescent and colorless or 

 slightly tinged with hemoglobin. Dried at low temperatures, a 

 beautifully transparent and entirely soluble scale antitoxin is ob- 

 tained. Large quantities of serum can easily be worked over in 

 this way at comparatively small expense. 



Tests show that the artificially concentrated antitoxin, kept in 

 small vials in an icebox, preserves its potency as well as or even 

 better than the ordinary antitoxic serum. Therapeutically, the 

 comparative results obtained are identical. Local irritation, rashes, 

 etc., seem to be less frequent and severe when the refined antitoxin 

 is administered. 



9 (101). " On the effect of magnesium salts upon the excita- 

 bility and conductivity of nerves " : S. J. MELTZER and 

 JOHN AUER. 



In their communication to this society on the anesthetic effect 

 of magnesium salts after subcutaneous injections, 1 the authors stated 

 that they made several series of experiments on the physiological 

 and pharmacological effects of these salts and that all their experi- 

 ments had demonstrated a common result, namely, that magnesium 

 salts produce a profound effect upon the nervous system and that 

 this effect is invariably of an inhibitory character. 



In their recent experiments the authors applied solutions of 

 magnesium salts to the sciatic, pneumogastric, depressor, and sym- 

 pathetic nerves of rabbits. Numerous applications of the magne- 



1 Proceedings of this Society, 1904-' 05, ii, p. 81. 



