RESEARCHES ON CFiLOROFORM ANiESTHESIA 649 



to understand the rate at which it is eliminated. According 

 to his experiments, the amount of the drug in venous blood 

 constantly exceeds that in arterial during recovery from chloro- 

 form narcosis. Expressed in other words, directly the adminis- 

 tration of the anaesthetic ceases the cells of the body begin 

 to discharge their associated chloroform, and with this their 

 functions gradually become restored. The subjoined table 

 from one of Tissot's papers is of interest : 



Milligrammes of CHCI3 per 100 grammes 

 of blood. 



In our own experiments,^ immediately the inhalation of 

 chloroform stopped, a sample of blood was taken from an 

 artery, and this was repeated at intervals, until half or three- 

 quarters of an hour had elapsed. In other experiments venous 

 blood taken close to the right ventricle of the heart was examined 

 in the same way, while in a few experiments samples of arterial 

 and venous blood were taken simultaneously. The main con- 

 clusion which can be drawn from these experiments is that 

 the rate of elimination of the drug from the body via the blood 

 depends upon the physiological state of the individual animal. 

 The rate of loss is at first comparatively rapid, and subsequently 

 becomes slower. But the initial rates of elimination are much 

 less rapid than the initial rates of the intake of chloroform, 

 and, on the whole, elimination is a much slower process than 

 assumption, a view which is supported not only by the actual 

 determinations of chloroform in the blood but by a comparison 

 of the times at which the various reflexes disappear and reappear. 

 From our curves the initial falls are not quite so rapid as the 

 work of other observers had led us to suppose. The chloro- 

 form-content of the blood was only reduced by 50 per cent, 

 in 15 to 20 minutes; three-quarters of the chloroform was 

 eliminated in about half an hour. These statements hold good 

 when the animal is breathing naturally, but, as might have 

 been expected, the extent to which the lung is being ventilated 

 during any period is the chief, if not the only, factor which 

 determines the rate of elimination. Our experiments are in 



* Buckmaster and Gardner, Proc. Roy. Soc, B., vol. Ixxix, 1907. 



