A CHEMICO-PHYSIOLOGICAL STUDY OF CER- 

 TAIN DERIVATIVES OF THE PROTEIDS.* 



BY R. H. CHITTENDEN, LAFAYETTE B. MENDEL, AND YAN- 

 DELL HENDERSON. 



THE marked activity which has characterized the study of 

 the proteids and their primary digestion or cleavage products 

 during the last decade has been especially manifest in two dis- 

 tinct directions. In the first place, effort has been directed 

 toward a study of the various transitions which these substan- 

 ces undergo in the several phases of digestion and nutrition, 

 with a view to obtaining clearer insight into the genetic rela- 

 tionship of the various chemical products and incidentally into 

 their chemical nature. In the second place, much attention 

 has been given to a study of the physiological action of the 

 more characteristic products of gastric and pancreatic proteoly- 

 sis, and more especially the behavior of these products when 

 introduced into the system through channels other than the 

 gastro-intestinal tract. This latter phase of physiological 

 research has been carried out in the majority of cases with a 

 mixed product resulting from the digestion of blood fibrin 

 with gastric juice, known as " Witte's pepton," and composed 

 of a variable proportion of proteoses with some true peptone. 

 It is needless to refer here in detail to the extensive litera- 

 ture which these latter investigations have created. It will 

 suffice to recall the fact that the more important observations 

 on the effect of so-called " peptones " when introduced directly 

 into the blood current were made by Schmidt-Mtilheim f and 

 Fano J in Ludwig's laboratory. The results they obtained 

 have in part become classic, and supplemented by certain later 

 observations made by other investigators may be briefly sum- 



* Reprinted from the'American Journal of Physiology, vol. ii. 

 t Schmidt-Mtilheim, Archiv f. Physiol., 1880, p. 30, 

 t Fano, Ibid., 1881, p. 277. 



