270 



Scientific Proceedings (116). 



4. The addition of both casein and yeast greatly improved 

 the growth and nutrition of the rats. As was to be expected from 

 the results with the addition of yeast alone, there was complete 

 protection afforded. 



The experiments here reported must be regarded as preliminary 

 to more detailed studies. The ease and certainty with which the 

 disease can be produced in rats cannot but make its experimental 

 study profitable, although it would be obviously premature to 

 apply the data already obtained to the problem of human rickets. 



137 (1719) 



Diffusible calcium in normal, rachitic, and 

 experimental tetany blood. 



By L. VON MEYSENBUG. 



[From the Department of Pathology, College of Physicians 

 and Surgeons, Columbia University, New York.] 



In 191 1, Rona and Takahashi 1 reported their work on the dif- 

 fusible Ca of horse, ox, and pig serum, finding an average of 65 

 per cent, of the total serum Ca to be diffusible. No work was done 

 with human blood. MacCallum, Lambert and Vogel 2 in 1914 made 

 the following statement: "If tetany blood be dialyzed under 

 exactly the same conditions as normal blood, it still loses a pro- 

 portionate amount of its Ca, which would perhaps show that it is 

 not especially the loss of a diffusible Ca as contrasted with a 

 non-diffusible form — which is important in producing tetany." 

 Brinkman 3 in 1919 advanced the hypothesis that the calcium-ion 

 concentration is dependent on the C0 2 tension of the blood. In 

 view of the altered blood C0 2 combining power found in tetany 

 by some workers, we have endeavored to correlate Brinkman 's 

 hypothesis with the low Ca content of the blood in tetany. During 



1 Rona and Takahashi, Biochem. Ztschr., 191 1, xxxi, 336. 



* MacCallum, Lambert and Vogel, Jour. Exp. Med., 1914, xx, 149. 



8 Brinkman, Biochem. Ztschr., 1919, xlv, 101. 



