THE INFLUENCE OF CHEMISTRY. 95 



1. Experiments icith non-nitrogenous Substances. 

 (Sugar, starch, gum, butler, etc.) 



Magendie fed a dog with sugar. The dog died on the 

 thirtieth day, in spite of large consumption during the first 

 period of the trial. Five-sixths of the muscles had disappeared, 

 and even the fat was gone. Similar results were obtained 

 when feeding butter ; the latter passed finally undigested 

 through the animal. 



Tiedemann and Gmclin fed geese with dextrine and with 

 starch. In the first instance the animal had died on the six- 

 teenlh day ; its weight had been reduced from five and two- 

 thirds to four and two-thirds pounds. In the second instance 

 the animal had lived twenty-seven days, and its weight had 

 been reduced from eight and a half to six and a quarter 

 pounds. 



2. Experiments ivith nitrogen containing organic Substances. 

 (White of the egg, flesh freed from fat, animal gehitine etc.) 



Magendie fed a lot of dogs with the white part of ego-s. 

 After a few days of the trial, they preferred to die by 

 starvation rather than to consume for any length of time 

 the rich nitrogenous food. A second lot of dogs were fed with 

 animal muscles freed from fat. They consumed, at the begin- 

 ning of the trial, every one of them, from one to two pounds 

 of that rich nitrogenous substance per day. All died between 

 from fifty to seventy-five days. A third lot were fed with 

 the animal gelatine obtained from the boiling of bones, wliiclt 

 they consumed at first freely. They all had died before the 

 twentieth day had passed by. The animals which served in 

 these experiments had in every case lost their muscles and their 

 fat. The result of these trials had left no doubt about the 

 fact, that a single proximate organic constituent of plants or 

 of animals, whether nitrogen-containing or not, could not be 

 considered in itself an efficient animal food. The reason why 

 it should be thus, or on what basis the various proximate 

 constituents of plants and of animals should be compounded 

 for a healthy animal diet, was evidently not yet understood. 



Phjsiologists and anatomists had studied during preceding 

 periods, the various manifestations of motion in the animal 



