RESEARCHES ON CHLOROFORM ANESTHESIA 641 



accounted for by an excessive exit of chloroform from the blood 

 into the tissues of the body, and especially the brain. On this 

 fact Tissot lays particular stress. It is clear, assuming that the 

 experimental data are beyond question, that the cause of death 

 must be ascribed not to a gradual process by which a slow, 

 progressive toxic stage is reached, but to a somewhat sudden 

 change, due to a rush of chloroform from the blood into the 

 body cells ; and if this occurs, it will become necessary for us to 

 modify our entire views as to the whole process of anaesthetisa- 

 tion : for other experimental evidence, some of which has been 

 already given, indicates that, with a definite pressure of chloro- 

 form in the blood, a definite constant effect is exerted upon the 

 cells of the body. These cannot and do not take up indefinite 

 quantities of chloroform ; they take it up in response to a 

 definite solution pressure which exists in the circulating liquids 

 of the body. This remarkable drop in the chloroform-content of 

 the blood we have not observed, though, in view of.Tissot's work, 

 the possibility that it might occur was especially considered. 



The method pursued by Buckmaster and Gardner in their 

 experiments was as follows : In all cases the percentage of 

 chloroform vapour in the inspired air was determined for each 

 separate experiment. The amount of chloroform in the blood 

 was estimated by the difference in chlorine-content of the blood 

 before the administration of chloroform, and again at any sub- 

 sequent period from the time when the chloroform-and-air 

 mixture ;was inhaled. The destiny of inhaled chloroform is 

 traced by its chlorine, and the blood during anaesthesia contains 

 an excess of this element. Numerous control experiments were 

 made in order to ascertain whether the percentage of chlorine 

 normally present in the blood of an animal remains sufficiently 

 constant during a prolonged experiment. This was found to 

 be the case when ether was the anaesthetic used. Small amounts 

 of blood withdrawn from time to time during such an experi- 

 ment were also found to in no way affect the percentage of 

 normal chlorine in blood. The chlorine was estimated by the 

 method of Carius, which is the one generally used for the deter- 

 mination of iodine, chlorine, or bromine in organic compounds. 

 A known weight of blood, about three to five grammes, is 

 treated with nitric acid, and an excess of solid silver nitrate in 

 a bomb tube heated to 200 C. for six hours. The amount of 

 resulting silver chloride was then determined, and the difference 



