Scientific Proceedings (48). 



term, seven lived for a few days after birth and all died in con- 

 vulsions, four were in utero when the mothers were killed and one 

 of these was deformed. 



All of the control matings were successful, all of the young lived 

 and were vigorous. 



51 (660) 



Growth and maintenance on purely artificial diets. 

 By Thomas b. Osborne and Lafayette b Mendel. 



[From the Laboratory of the Connecticut Agricultural Experiment 

 Station, and the Sheffield Laboratory of Physiological Chemistry 

 in Yale University, New Haven, Connecticut.] 



[With the cooperation of the Carnegie Institution of Washington.] 



In earlier reports of the authors' feeding experiments with 

 isolated food substances 1 attention was directed to the failure to 

 induce growth or secure prolonged maintenance of body weight in 

 albino rats with any of the food mixtures tried prior to the intro- 

 duction of "protein-free milk" as the adjuvant of the dietary 

 which furnished the inorganic nutrients together with some of the 

 carbohydrate (in the form of lactose). In order to determine 

 whether the nutritive success achieved by the use of the protein- 

 free milk was due to the peculiar supply of inorganic salts or some 

 other ingredient, an artificial mixture of salts was prepared to 

 imitate as nearly as possible the proportions of acid and basic 

 radicals in the milk product. This mixture, the preparation of 

 which will be described in detail in a forthcoming paper, contains : 

 Cai.97; Mgo.23; Na2.03; K 2.66; P0 4 3.33; CI 4.13; SO3O.30; 

 Fe 0.04; citric acid 3.33; lactose 82.0 per cent. This purely arti- 

 ficial product added to purified proteins, starch, sugar and lard 

 has already sufficed to meet the needs of rats for maintenance over 

 very considerable periods of time, and has, thus far, proved as 

 efficient in promoting early growth as the so-called protein-free 

 milk used in our former experiments. 



1 Osborne, T. B., and L. B. Mendel, Carnegie Institution of Washington, Pub- 

 lication 156, Part II, 1911; and Science, 1911, XXXIV, p. 722. 



