42 2 THE POPULAR SCIENCE MONTHLY 



digestion through a fistula following a gunshot wound in the case of 

 the Canadian Alexis Saint Martin, the results being published in 1833, 

 These observations constituted an important contribution to the subject 

 and attracted world-wide attention. 



Leuchs in 1831 discovered the starch-digesting properties of saliva. 

 Payen and Persoz in ISSS discovered and studied the amylolytic ferment 

 diastase in germinating barley. Mialhe in 1845 isolated ptyalin from 

 saliva. 



J. N. Eberle in a work published in 1834 was the first to note the 

 power of an extract or artificial gastric juice prepared from the gastric 

 mucous membrane to dissolve proteid material. He, however, errone- 

 ously attributed this solvent action to the mucus on the surface of the 

 stomach. Theodor Schwann (1810-1882), the discoverer of animal 

 cells, investigated the subject (partly in association with his teacher 

 Johannes Mliller) and in crude form isolated from the gastric mucosa 

 a principle possessing intense proteolytic powers, to which he gave the 

 name pepsin; his results were published in 1836. 



In his treatise published in 1834 Eberle noted the fact that a watery 

 extract of the pancreas would emulsify oil, and he surmised that one of 

 the functions of the pancreatic secretion was to favor the absorption of 

 fat. In 1836 Purkinje and Pappenheim discovered that extracts from 

 the pancreas possess proteolytic properties. In 1844 Valentin made 

 some observations on the starch-digesting powers of the pancreatic 

 fluid; and in 1845 Bouchardat and Sandras definitely demonstrated the 

 secretion of an amylolytic principle by this organ. 



Following these pioneer discoveries, the elucidation of the functions 

 of the pancreas, especially its fat-splitting action, was accomplished 

 chiefly by the work of the French investigator Claude Bernard (1813- 

 1878), whose researches on this subject were prosecuted about 1836- 

 1846. 



From these beginnings the chemistry and physiology of digestion 

 have been further elaborated by numerous subsequent investigators. 



The study of gastric digestion was made a simple clinical procedure 

 by the employment of the stomach tube for obtaining samples of gastric 

 juice. This originated with Adolph Kussmaul (18'22-190'2), who in 

 1869 reported the use of the stomach tube in the treatment of dilata- 

 tion of the stomach; subsequent to which the examination of gastric 

 juice for diagnostic purposes was elaborated by "W. 0. Leube, C. A. 

 Ewald and Franz Riegel, and their associates during the seventies and 

 eighties of the last century. 



Important studies of the action of the digestive organs were not long 

 ago made by Ivan Pyotrovich PavlofI (often transliterated, from the 

 German, J. P. Pawlow) (born 1849), director of the Imperial Insti- 

 tute of Experimental Medicine in Saint Petersburg, the results of whose 

 brilliant researches (conducted 1887-1897) were first published in col- 



