408 Enzymcs as Factors in Edema [Mar. 



we have occasionally been at work on various aspects of these sub- 

 jects. Berg's "comparative study of the digestibility of different 

 proteins in pepsin-acid Solutions "^ was the first and most detailed 

 subsequent contribution in this connection. At various times during 

 the last two years, Miss Tula L. Harkey, Professor Wm. H. 

 Welker, Dr. F. G. Goodridge, and Messrs. John L. Kantor, Samuel 

 Gitlow, Edgar G. Miller, Jr., and the junior author have coöp- 

 erated in extensions of the work. The results will be prepared for 

 publication as soon as it is convenient to do so. We present in this 

 paper the results of some of the experiments which were performed 

 by the junior author during the past winter. 



EXPERIMENTAL. GENERAL PROCEDURE 



The preliminary observations by Berg and Gies,^ on the power 

 of proteases to increase protein hydrophilia in acid and alkalin 

 Solutions, have been confirmed by quantitative methods in these 

 experiments. The absolute amounts of water absorbed by weighed 

 quantities of comparatively pure protein products, from given acid 

 and alkalin enzyme Solutions, were ascertained by accurate meas- 

 urements of the volumes of the corresponding filtrates obtained 

 minder conditions of experimental uniformity.^ Typical summaries 

 from our records in this connection are appended. 



FIRST SERIES OF EXPERIMENTS 



« 



With fibrin and pepsin in o.i per cent. hydrochloric acid Solution 



I. Conditions of the first experiment: Weighed quantities 

 of fibrin (3 grams) were transferred to six tall narrow glass-stop- 

 pered graduated bottles (250 c.c). The fibrin was treated there, 

 in each case, with 250 c.c. of o.i per cent. hydrochloric acid Solution. 

 To each mixture, except the control, a definite amount of dilute 

 pepsin^ Solution was added promptly, and the contents of the bottle 

 were gently shaken at once. The concentration of the pepsin prod- 

 uct in the stock Solution specially prepared for use in the experiment 



' Berg : American Journal of Physiology, 1909, xxiii, p. 420. 

 * Berg and Gies : loc. cit. 



" Brod : Beiträge zur Lehre von der Eiweissverdauung. Dissertation, 

 Würzburg, 1892. 



*An ordinary commercial product was used in each experiment. 



