CHAP. IX.] THE ENZYMES OF THE INTESTINAL JUICE. 413 



of raw fibrin, whilst Schiff asserted that in the case of successful 

 fistulge, all proteids are digested and converted into peptones, if 

 introduced within the intestine. Subsequent observers, however, 

 such as v. Wittich 1 , Quincke 2 , Demant 3 , Paschutin 4 , using different 

 methods, were unable to confirm the observations of Thiry, Leube 

 and Schiff. 



The most recent researches (Masloff, Wenz) have clearly proved 

 that neither the mucous membrane of the small intestine nor the 

 juice which it secretes, contain enzymes capable of converting pro- 

 teids into albumoses and peptones, under the conditions which exist 

 in the small intestine. 



Masloff 5 , in a research conducted in Kiihne's laboratory, has shewn 

 that the succus entericus has no action on proteids provided that 

 the influence of putrefactive organisms be prevented by the addition 

 of thymol. If acidified, the intestinal juice exerts (according to 

 Masloff) a very slight solvent action on fibrin, due to the presence, 

 obviously, of a trace of pepsin, the physiological importance of 

 which is altogether insignificant. Masloff found that proteids of 

 various kinds introduced into a Thiry fistula underwent no change 

 in the course of 24 hours. Wenz 6 has further shewn that the albu- 

 moses are not converted into peptones by the intestinal juice. 



It is therefore clear that the changes observed to occur by Thiry 

 and Schiff, when fibrin and other proteids were introduced into the 

 intestine of dogs, were the result of a putrefactive process. 

 Action of the J n spite of the negative statements of many of the 

 earlier observers ( Thil 7> Leube > Schiff > and v - Wittich) 7 , 



e 

 fer- there is now no doubt whatever that the small in- 



ment of the in- testine possesses the power of converting starch into 

 testinai juice, maltose (Brown and Heron 8 , Gumilewski 9 , Rohmann 10 , 

 Dobroslawin 11 , Lannois and Lepine la , &c.). Rohmann's observations 



1 v. Wittich, Archivf. Phys. Vol. n. p. 193. 



2 H. Quincke, ' Ueber die Ausscheidung von Arzneistoffen durch die Darmschleim- 

 haut,' Archivf. Anat. u. Phys. 1868, p. 150. 



3 B. Demant, op. cit. Virchow's Archiv, Vol. LXXV. (1879), p. 419. 



4 Victor Paschutin, ' Einige Versuche mit Fermenten, welche Starke und Eohrzucker 

 in Traubenzucker verwandeln,' Archiv f. Anat. u. Phys. 1871, p. 305. 



5 A. Masloff, ' Zur Diinndarmverdauung, ' Kiihne's Untersuchungen, &c. Vol. n. 

 p. 920, Heidelberg, 1882. 



6 Wenz, ' Ueber das Verhalten der Eiweissstoffe bei der Darmverdauung,' Zeitschrift 

 f. Biologie, Vol. xxii. 1886, p. 1. 



7 Bidder and Schmidt and Frerichs must be mentioned as early experimenters 

 who attributed a diastatic action to the intestinal juice. 



8 Horace T. Brown and John Heron, ' Die hydrolytischen Wirkungen des Pankreas 

 und des Dunndarms,' Annalen d. Chemie u. Pharmacie, Vol. cciv. (1880), pp. 228251. 



9 Gumilewski, Pfliiger's Archiv, Vol. xxxix. (1886), p. 556. 



- F. Rohmann, ' Ueber die diastatische Wirkung des Darmsaftes und die Resorption 

 vom Starkekleister,' op. cit. Pfliiger's Archiv, Vol. XLI. (1887), p. 424. 



11 A. Dobroslawin, ' Beitrage zur Physiologic des Darmsaftes,' Untersuchung. aus d. 

 Inst. f. Phys. u. Hist, in Graz, Leipzig, 1870. 



12 Lannois and Lepine, ' Sur la maniere differente dont se comportent les parties 

 superieures et inferieures de 1'intestin grele au point de vue de 1'absorption et de la 

 transudation,' Archives de Physiologic, 1883, T. i. p. 92. 



