NECESSITY OF A VARIED DIET. 131 



which bear particularly on the questions under consideration, 

 were the following : 



"Gelatine, albumen, fibrin, taken separately, do not 

 nourish animals except for a very limited period and in a 

 very incomplete manner. In general, these substances soon 

 excite an insurmountable disgust r to the point that animals 

 prefer to die of hunger rather than touch them. 



" The same principles artificially combined and rendered 

 agreeably sapid by seasoning are accepted more readily and 

 longer than if they were isolated, but ultimately they have 

 no better influence on nutrition, for animals that take them, 

 even in considerable quantity, finally die with all the signs 

 of complete inanition. 



" Muscular flesh, in which gelatine, albumen, and fibrin 

 are united according to the laws of organic nature, and when 

 they are associated with other matters, such as fat, salts, etc., 

 suffices, even in very small quantity, for complete and pro- 

 longed nutrition." 1 



In Burdach's treatise on physiology, is an account of some 

 interesting experiments by Ernest Burdach on rabbits, show- 

 ing the influence of a restricted diet upon nutrition. Three 

 young rabbits from the same litter were experimented upon. 

 One was fed with potato alone, and died on the thirteenth 

 day with all the appearances of inanition. Another fed on 

 barley alone, died in the same way during the fourth week. 

 The third was fed alternately day by day with potato and 

 barley, for three weeks, and afterward with potato and bar- 

 ley given together. This one increased in size and was per- 

 fectly well nourished. 2 



In 1769, long before any of the above-mentioned experi- 

 ments were performed, Dr. Stark, a young English physiol- 

 ogist, fell a victim at an early age to ill-judged experiments 

 on his own person on the physiological effects of different 



1 Op. dt., p. 282. 



2 C. F. BURDACH, Traitc de Physiologic, traduit par JOURDAN, Paris, 1841, 

 tome ix., p. 249. 



