. V. INORGANIC CONSTITUENTS. 115 



hydrogen. Evidently a large quantity of atmospheric air is 

 introduced into the stomach: that is to say, it is swallowed 

 with the food. The oxygen of the air disappears in the 

 stomach, perhaps by filtration through the membranes, and 

 reaches the blood ; or, what is still more probable, by taking 

 part in those modifications which we know occur in order 

 to transform the azotised albuminous substances into fer- 

 ment. Carbonic acid appears very abundantly developed 

 in this case ; and the enormous volumes of this gas, which 

 is disengaged in some animals fed on fresh and moist herbs, 

 may be here referred to. 



It is curious to observe, that the production and disap- 

 pearance of this abundant quantity of gas in the stomach 

 and intestines, take place and succeed each other sometimes 

 with so much rapidity, that one cannot have recourse to 

 chemical reactions to explain them. The presence of hy- 

 drogen cannot, at present, be referred to any of the physico- 

 chemical changes which we have seen to take place during 

 digestion. 



I have shown, by experiment, that oxygen is not neces- 

 sary to the solvent action which the gastric juice exercises 

 on fibrine and coagulated albumen, as Liebig seems to sup- 

 pose. A piece of the stomach of a pig was put, along with 

 some fibrine and coagulated albumen, into slightly acidu- 

 lated water; the water had boiled for several hours, and the 

 prepared liquid was covered with a thick film of oil. The 

 fibrine and albumen were dissolved in this bath quite as 

 well as in another similar one which was left in contact 

 with the air. 



Inorganic Constituents of the Body. The inorganic sub- 

 stances found in the organism, have been evidently intro- 

 duced from without, and formed part of the aliments : they 

 cannot reach the blood unless they have been dissolved in 

 water, and in the gastric juice of the stomach. "Whatever 



