EXPERIMENTATION AND PHYSIOLOGY 



injury or disease, the function of this gland 

 becomes much impaired sugar appears in the 

 urine. A man sustains an injury to the abdo- 

 men and sugar appears in the urine; before 

 animal experimentation had shown this rela- 

 tion it was never suspected that this sign meant 

 injury of the pancreas. 



During the development of these studies 

 many interesting and puzzling questions have 

 arisen. John Hunter asked, Why does not 

 the stomach digest itself? This question was 

 answered by theories until Bernard introduced 

 the leg of a living frog into the stomach of a 

 dog. This was followed by the experiment 

 of tying certain blood vessels of the stomach, 

 shutting off the circulation from certain areas, 

 and observing that the mucous membrane of 

 these areas became digested. Out of these 

 studies has come our understanding of the 

 nature of ulcer of the stomach, which is now 

 treated with success never before attained. 



The knowledge of the absorption of digested Assimila- 

 nutriment dates from that memorable day in tion. 

 1662 when Aselli exposed the mesentery of a 

 dog after a full meal and observed a network 

 of curious white lines under the peritoneum 

 passing from the bowel. These were absent 



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