54 



Scientific Proceedings (56). 



When extracardial pressures equal to those previously existing 

 in the closed thorax are applied, however, the records so far ob- 

 tained show no alteration in the steepness of the curve, nor is 

 any difference discernible when the cardiometer is left open to 

 the air or in communication with a tambour within which a 

 pressure equal to 15 mm. of water develops during systole. 

 Furthermore, the records taken from naturally breathing animals 

 by a sound correctly placed within the ventricular cavity also show 

 no decreased incline of the isometric rise; in fact, some records 

 reveal a slightly steeper curve during inspiration. 



These results indicate that such negative pressures as are 

 normally developed within the chest during cardiac systole or the 

 acts of inspiration are without direct effect on intraventricular 

 pressure and hence cannot be responsible for the fall of arterial 

 pressures during inspiration. 



32 (849) 



The effect of gentian violet on enzymes, toxines and ultra-micro- 

 scopic infections. 



By John W. Churchman. 



[From the Laboratory of Surgery, Yale University.] 



Since the observations reported by me, two years ago, on the 

 effect of gentian violet on bacteria, studies have been carried on 

 to extend these observations into the field of enzymes, toxines 

 and ultra-microscopic infections. The original purpose of these 

 experiments was to offer a new method of studying ultra-micro- 

 scopic infections and to see if it might not be possible, by adding 

 a dye to an infectious agent, to stain and thus to kill organisms 

 too small to be seen. Experiments of a similar nature are now 

 under way in this laboratory with inoculable tumors. 



The following groups of active agents have thus far been 

 studied: 



1. Organized ferments (yeast). Yeast cells when stained with 

 gentian violet lose entirely their power of fermenting sugar. 



2. Unorganized ferments, (a) Ptyalin (salivary diastase)- 

 This ferment when stained with gentian violet is quite as active as 



