GASTRIC JUICE. 



51 



to obtain it unmixed with the other secretions. These 

 are the causes of the conflicting results which experi- 

 ments made to ascertain the composition of the gastric 

 juice, have generally presented. Later experimenters, 

 by whom these circumstances have been kept in view, 

 have found it composed chiefly of water, mucus, alka- 

 line sulphates (chiefly soda,) hydrochlorates, phosphates, 

 muriate of lime, and a few other salts in minute propor- 

 tions. The acidity is occasioned by the presence of hy- 

 drocloric and acetic acid. 



The gastric juice is not only a powerful solvent, but 

 has remarkable coagulating and anti-putrescent powers. 

 Dr. Fordyce states that five or six grains of the mucous 

 coat of the stomach from which it is no doubt secre- 

 ted infused in water, gave a liquor which coagulated 

 more than a hundred ounces of milk. We find that 

 milk when taken into the stomach is invariably coagula- 

 ted before digestion can take place. Of its antiputres- 

 cent qualities there is abundant proof. The fact has 

 been frequently verified by experiments, that putrid meat 

 by being introduced into the stomach of animals, will 

 after a short time become perfectly sweet. It has been 

 ascertained that the gastric juice of the dog and crow 

 will preserve veal and mutton thirty days ; whereas the 

 same meat kept immersed in water will give out a foetid 

 smell as soon as the seventh day, and become perfectly 

 offensive on the thirtieth. 



Emily. I should think that the digestive powers of 

 the gastric juice might be satisfactorily tested by obtain- 

 ing it from the stomach of some animal, and immersing 

 different articles of food into it. I should be delighted 

 to witness its effects. Cannot we try the experiment ? 



Dr. B. We may spare ourselves that trouble, for 

 your idea has been anticipated long ago, by many phys- 

 iologists. 



Emily. And with what success did they meet ? 



Dr. B. It could not be rationally expected that out 

 of the body, beyond the influence of the vital powers. 



