350 Messrs. G. A. Buckmaster and J. A. Gardner. [Aug. 19, 



prior to anaesthetisation. When the hyperpnoea is marked, or the percentage 

 of chloroform inhaled is high, the percentage of chloroform in the blood rises 

 with great rapidity to a maximum value, and the activity of the respiratory 

 centre is depressed ; this may occur to such an extent that the animal ceases 

 to respire with the diaphragm always in the state of rest. This is illustrated 

 by the following tracings of six experiments selected from a greater number 

 (figs. 1 to 6):— 



Experiment 1. — Effect of 1*5 per cent, chloroform after deep respirations 

 (%•!):- 



Fig. 1. 



Depth of respiration, 1 division = 21*74 c.c. ; time intervals, 30 sees ; |, chloroform on„ 



Table I. — Measurements of Tracing in Fig. 1. 



Intervals 

 of time, 

 in minutes. 



Anaesthetic. 



No. of 

 respirations 

 per minute. 



Average depth 

 of respiration, 

 in c.c. 



ventilation, 



1 







54 



94 -79 



5119 



0-5 



1 -5 per cent. CHC1 3 



32 



75 -67 





0-5 



26 



55-0 



5£}«« 



1 





54 



47 -19 



2548 



The remaining data of this experiment are given in Curve I, which shows 

 the effect of chloroform (1*5 per cent.) for 11 minutes, recovery for 8 minutes, 

 r 3- chloroforming with 1*5 per cent, for 16 minutes, recovery for 9 minutes, 

 and, finally, re-chloroforming again with 2 per cent., death resulting in 

 43 minutes, in the 87th minute after the commencement of the experiment. 



