82 THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
of flow indicates a vasoconstrictor action by the CHC1 ? on the cardiac vessels ; for 
the difference was so great as to be inexplicable by the loss of the power of the cardiac 
contractions or by a slight increase in the viscosity of the solution. [Subsequent to the 
printing of this paragraph of our Report to the Committee there has appeared a note by 
Professor Schafer and Dr. Scharlieb 8 on the action of chloroform on the blood- 
vessels, from which it is clear that chloroform causes contraction of blood-vessels 
through which it is perfused]. 
Alteration in Frequence of the Beat-Rate 
As several times mentioned above, we have remarked, with surprise, the usual 
absence of any alteration of frequence or rhythm of beat-rate in the isolated mam- 
malian heart, perfused with dilute chloroform solution. Certainly, in most cases, the 
heart-beat in our experiments has suffered reduction in its amplitude in degree varying 
with the concentration of the chloroform, without suffering any appreciable change in 
beat-rate either as to frequence or to rhythm. But we have not yet measured out 
our curves sufficiently to say that diminution of frequence does never occur. 
Fig. 13. Cat's heart. Experiment 27, observation 1. CHCl, one part in 50,000 of modified Ringer's 
fluid ; 78 c.c. perfused in one minute ten seconds. 
