Phosphate and Calcium Content of Serum. 143 



The technic of the method is as follows: To 8 c.c. of water in a 

 50 c.c. centrifuge tube is added 1 c.c. of the extract to be examined, 

 and the solution warmed to just 40 0 C. in a water bath with ther- 

 mostat attachment. One c.c. of one per cent, cane sugar is now 

 added and incubation carried out for 30 minutes. The solution is 

 rapidly cooled in cold water and 0.5 to 1.0 gram of dry picric acid 

 added, thoroughly mixed, centrifuged and filtered. The inverted 

 sugar is now estimated colorimetrically in 3 c.c. portions as already 

 described. 1 



One must not let the sucrose stand for a long time in contact 

 with the picric acid, owing to the hydrolytic action of the picric 

 acid. 2 For this reason it might be of advantage to employ sodium 

 picrate, as recently recommended by Benedict. 3 



Utilizing the above method we have been unable to satis- 

 factorily demonstrate sucrase in human blood or that of rabbits. 

 With one per cent, yeast extract there was 60 per cent, inversion 

 in one-half hour, i. e., 6 of the 10 mg. were inverted, while a one 

 per cent, yeast extract in human blood gave a 54 per cent, inver- 

 sion. With a 10 per cent, extract of the mucous membrane of 

 rabbit's intestine figures of 13.2 and 12.8 per cent, were obtained. 

 Controls were all negative. 



195 (1373) 



The phosphate and calcium content of serum in the condition of 



guanidine tetany. 



By C. K. Watanabe. 



[From the Laboratory of Pathological Chemistry, School of Medicine, 

 and The Sheffield Laboratory of Physiological Chemistry, Yale 

 University, New Haven.] 



In the altered metabolism in parathyroidectomized dogs, 

 Greenwald 4 found a marked decrease in the elimination of phos- 

 phate in the urine together with a distinct retention in the blood. 



1 Myers and Bailey, Jour. Biol. Chem., 1916, XXIV, 147. 



2 Rose, these Proceedings, 1917, XX, 16. 



3 Benedict, Jour. Biol. Chem., 1918, XXXIV, 203. 



4 Greenwald, L, Am. Jour. Physiol., 1911, XXVIII, 103. 

 Greenwald, I., J. Biol. Chem., 1913, XIV, 363; Ibid., 1913, XIV, 369. 



