Digitalis Assay 



285 



tion caused increased permeability and the acid diffused out. This 

 effect could not be obtained with currents too weak to cause the 

 bleb formation previously described. 



III. Mrs. Harvey states that the tentacle coils at the make 

 remains coiled while the current is passing and relaxes at the 

 break. This is true for certain individuals and certain positions 

 of the organisms relative to the current direction, but not for 

 all. There is considerable variety of detail for which the read- 

 er is referred to a fuller report to be published later. When 

 the current is from aboral to oral the usual effect is as follows : 

 Strong contraction of tentacle at make; held contracted nearly 

 to full extent while current is passing; slight contraction (some- 

 times none) at break followed by marked relaxation. When 

 current is oral to aboral : extreme relaxation at the make (some- 

 times preceded by a slight instantaneous contraction) ; held re- 

 laxed while current is passing; strong contraction at break, fol- 

 lowed by return to normal position. Often spontaneous to and 

 fro movement was seen either in the strongly contracted or 

 strongly relaxed tentacle while current was passing. These ef- 

 fects of the current seem explicable on the basis of electrotonus. 



137 (2097) 



Observations on the assay and factors influencing the quality 



of digitalis. 



By E. L. NEWCOMB. 



[From the University of Minnesota, Minneapolis, Minnesota.] 



A method for assaying digitalis and other drugs of this group 

 by the use of cats was outlined. The procedure was practically 

 identical with the Hatcher-Ouabain Method, as published in the 

 American Journal of Pharmacy, 1910, but differed in the im- 

 portant point of completing the test with the digitalis to be 

 standardized, rather than with a standard Ouabain solution. 

 Results by this method, it was stated, were comparable with 

 those obtained with Ouabain, and as accurate as the use of frogs 

 or guinea pigs for determining toxicity. Regulating the dose 



