Scientific Proceedings. 



strated the untrustworthiness of any such differentiation of the 

 anti-bodies as those contained in the euglobulin and those of the 

 pseudoglobulin. No evidence has been adduced from our experi- 

 ments to show that the agglutinins developed in the rabbit, goat 

 and horse can be classed as belonging to either globulin, or that 

 these anti-bodies can be separated from one another by ammo- 

 nium sulphate fractioning of polyagglutinative sera. 



16 (159) 



Further observations of the effects of ions on the activity of 



enzymes. 



By WILLIAM N. BERG and WILLIAM J. GlES. 



\_From the Laboratory of Biological Chemistry of Columbia Uni- 

 versity, at the College of Physicians and Surgeons^ 



Previous communications from this laboratory 1 have made it 

 evident that peptolysis of fibrin is unequal in rate and extent in 

 acid solutions of equipercentage, equinormal (isohydric), equimolec- 

 ular, or equidissociated (isohydrionic) concentration. The same 

 may be said of tryptolysis of the same protein in a series of bases 

 of analogous concentrations. 



We have found that the sequence of zymolysis, both in rate 

 and extent in a given group of acid or basic solutions, varies con- 

 siderably with the nature of the protein. This fact makes it im- 

 possible accurately to formulate statements regarding various 

 phases of peptolysis or tryptolysis without specifying the particular 

 protein involved in the process ; it also renders doubtful various 

 general conclusions of common acceptance pertaining to digestion 

 that have been derived, in one research or another, from the use 

 of a single protein. A study of the peptolysis of many proteins 



1 Gies : American Journal of Physiology, 1903, viii (Proceedings of the American 

 Physiological Society, 1902, p. xxxiv) ; the same journal, 1903, ix (Proceedings of 

 the same Society, 1903, p. xvii) ; Gies and collaborators : Biochemical Researches, 

 1903, i, pp. 61-63. Also Berg (communicated by Gies) : Science, 1906, xxiii, p. 335 

 (Proceedings of the Section of Biological Chemistry of the American Chemical Society 

 in affiliation with Section C (Chemistry) of the American Association for the Advance- 

 ment of Science, 1905); Proceedings of the American Association for the Advancement 

 of Science, 1906, p. 331. 



