ORGANIC PRINCIPLE OF THE GASTKIC JUICE. 235 



in this case there is reason to suppose that the secretion was 

 not normal. The analysis of the gastric juice of St. Martin 

 ' by Berzelius was not minute. The analyses of Schmidt give 

 less than six parts per thousand of solid matter ; while Ber- 

 zelius found over twelve parts per thousand. In all the 

 comparatively recent analyses, there have been found a free 

 acid or acids ; a peculiar organic matter, generally called 

 pepsin ; and various inorganic salts, among which may be 

 mentioned as most important, the chlorides of sodium, po- 

 tassium, and calcium, with the phosphates of lime, mag- 

 nesia, and iron. Of these constituents, the salts possess little 

 physiological importance compared with the organic matter 

 and the acid principles. 



Organic Principle of the Gastric Juice. This principle, 

 called pepsin or gasterase, is an organic nitrogenized body, 

 peculiar to the gastric juice ; and, as we shall see further on, 

 is essential to its digestive properties. When the gastric fluid 

 was first obtained, even by the imperfect methods employed 

 anterior to the observations of Beaumont and of Blondlot, an 

 organic matter w r as spoken of as one of its constituents. In 

 the rough analyses given by Leuret and Lassaigne, in 1825, 

 an " animal matter soluble in water " is mentioned ; 1 Tiede- 

 mann and Gmelin speak of " an animal matter insoluble in 

 alcohol, but soluble in water," which they regarded as sali- 

 vary matter, and another animal matter, soluble in alcohol 

 (osmazome) ; " and, finally, in a letter to Dr. Beaumont, Dr. 

 Dunglison states that in conjunction with Professor Emmet, 

 of the University of Virginia, he found in a specimen of gas- 

 tric juice taken from St. Martin " an animal matter, solu- 

 ble in cold water, but insoluble in hot." ! This principle 



1 LEURET ET LASSAIGNE, Recherches Physiologiques et Chimiques pour servir 

 d I'Histoire de la Digestion, Paris, 1825, p. 113. 



2 TIEDEMANN ET GMELIN, Recherches Experimentales Physiologiques et Chi- 

 miques sur la Digestion, Paris, 1827, premiere partie, p. 168. 



3 BEAUMONT, Experiments and Observations on the Gastric Juice, and the Phys- 

 iology of Digestion, Plattsburg, 1833, p. 78. 



