86 THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
Mammalian Heart Perfused with Diluted Blood Containing ioo mgrms. 
of Chloroform per Litre 
An experiment in which the heart was perfused with diluted blood showed 
the CHC1 3 to be much less potent in this medium than in ' modified Ringer's solu- 
tion.' At a strength of I in 10,000 by weight or 100 mgrms. to a litre, the ventricle's 
beat was reduced by 30 per cent, in Observation 1, by 32 per cent, in Observation 2. 
The reduction which we should expect a similar dilution of chloroform in modified 
Ringer's fluid to produce, would be between 80 per cent, and 90 per cent, of the 
ventricular beat. The amounts perfused were: Observation 1, 9*5 c.c. in one minute 
fifty seconds, Observation 2, 10 c.c. in three minutes twelve seconds. The blood 
was diluted with an equal volume of Locke's solution. 
Observations on the Human Heart 
In two instances we have had opportuity to examine CHC1 3 dosage for the 
isolated human heart. In the first case, observations were commenced six hours post- 
mortem ; in the second, a still-born child, three hours after delivery. The fluid per- 
fused was, in the former case, ' modified Ringer,' in the latter, ' Locke's solution.' 
With a strength of CHC1 5 solution of 100 mgrms. per litre (1 in 10,000), the reduc- 
tion (average) of the auricular beat was 76*5 per cent. ; of the ventricular was 92 per 
cent. The results were therefore quite in conformity with those given by the cat 
hearts. Fig 14 shows one of the records obtained in the second of the above cases. 
J » 0 11 I I I 1 \ 1 q 
A. 
V. 
Time in 5 sees 
Signal for 
chloroform 
Fig. 14. Experiment 52. Observatory. Human heart perfused with CHC1 3 100 mgrms. per litre, Locke's solution. 
Time marked every fifth second. An interval of two -minutes between the encl "of Trace 1 and beginning of Trace 2. 
CHCl, was perfused for eighty seconds. A, auricular beat ; V, ventricular beat. 
