ARTIFICIAL FOODS. 847 



and carbohydrates. 1 But it has been positively demonstrated that they 

 can be kept alive a long time by feeding exclusively with meat freed as 

 much as possible from visible fat (PFLUGER 2 ). Human beings and 

 herbivora, on the contrary, cannot live for any length of time on such 

 food. On one hand they lose the property of digesting and assimilating 

 the necessarily large amounts of meat, and on the other a distaste for 

 large quantities of meat or proteins soon appears. 



A question of greater importance is whether it is possible to maintain 

 life in an animal for any length of time with a mixture of simple organic 

 and inorganic foodstuffs. This was not possible in the experiments of 

 BUNGE and LUNIN, cited above. Later investigators, such as HALL and 

 STEINITZ, FALTA and NOEGGERATH, KNAPP and JACOB have come to the 

 same conclusion, although they obtained somewhat better results. ROH- 

 MANN 3 obtained much better results, and he showed that the selection of 

 the protein is of the greatest importance. " If mice are fed with a mixture 

 of 7.2 parts vitellin, 14 parts casein, 4 egg albumin, 27 margarine, 120 

 wheat starch, 60 potato starch, 10 dextrose, 4 salts (a mixture of 10 parts 

 calcium phosphate, 40 acid potassium phosphate, 20 sodium chloride, 

 15 sodium citrate, 8 magnesium citrate, 8 calcium lactate) it is not only 

 possible to keep all the mice alive for some time but it is also possible to 

 raise young mice by artificial feeding of the mother and then the small 

 animals themselves (RoHMANN 4 ). They become mature and deliver 

 active offspring who in turn become mature. The young that these 

 deliver cannot be raised to maturity." If the food only contained one 

 of the above-mentioned proteins the adult mice lost weight and succumbed 

 after a certain time. If the casein is replaced by egg albumin or the egg 

 albumin was replaced by casein the weight of all the mice remained con- 

 stant for some time. Young mice had their development retarded in a 

 remarkable manner. They remained at the same body weight for some 

 time and then succumbed. 



These experiments show that the various proteins have different 

 importance in nutrition and especially for the develpoment of the young. 



1 See Horbaczewski, Maly's Jahresber., 31, 715. 



2 Pfliiger's Arch., 50. 



3 Hall, Arch. f. (Anat. u.) PhysioL, 1896; Steinitz, Ueber Versuche mit kiinstlicher 

 Ernalirung, Inaug.-Diss., Breslau, 1900; Falta and Noeggerath, Hofmeister's Beitrage, 

 7; Knapp, Zeitschr. f. exp. Path. u. Therap., 5; Jacob, Zeitschr. f. Biol., 48; Rohmann, 

 Klin, therap. Wochenschr., No. 4, 1902 and Allg. med. Zentral.-Zeitg., 1908, No. 9. 



4 Allg. med. Zentral-Zeitg., 1908, No. 9. 



