Scientific Proceedings (107). 



been found in the few experiments which have so far been done 

 that T wave changes occurred uniformly and that the blood pres- 

 sure usually rose, the increase varying from 20 to 66 mm. Hg. 



Data on the effect of the drugs on rate and on conduction are 

 reserved for later publication and likewise detailed descriptions of 

 differences between the two drugs. 



Conclusions. 



With doses of therapeutic range equal to 30 per cent, of the 

 calculated lethal dose, digitalis and strophanthin (1) increased 

 the contractile power of the cardiac muscle, and by so doing in- 

 creased the volume output. This effect supplies a firm basis for 

 the statement that these drugs may exercise a beneficial action. 

 (2) At the same time, the T wave is usually altered, and (3) there 

 is a transient elevation of blood pressure. 



86 (1546) 



A method for the estimation of lactic acid in blood. 



By George A. Harrop, Jr. (by invitation). 



{From the Chemical Division of the Medical Department of Johns 

 Hopkins Hospital, Baltimore.] 



The procedure is based upon the observation of Deniges 1 

 that lactic acid, in the presence of concentrated sulphuric acid, is 

 converted into acetaldehyde, and can then be detected by certain 

 reagents, particularly phenols and morphine alkaloids. 



5 c.c. of untreated whole blood or serum is delivered directly 

 into 15 c.c. of acidified copper sulphate solution, the flask being 

 in the meanwhile gently shaken. It is heated 4-5 minutes on 

 the water bath, cooled, and an excess of powdered calcium hydrate 

 is added. It is then allowed to stand for 30 minutes and filtered. 

 A water-clear solution is obtained which is free from sugar and 

 other aldehyde forming substances, and which does not char 

 appreciably during the subsequent treatment with sulphuric acid. 

 One part of filtrate is added cautiously to 4 parts of pure concen- 

 trated sulphuric acid, the mixture being meantime shaken and 



1 G. Denigds, Ann. de Chem. et de Phys. (8), 18, 149. 



