420 Messrs. G. A. Buckmaster and J. A. Gardner. [July 11, 



Tissot's deduction from this diminution in the blood which is constant just 

 before death is that the choroform of the blood passes into and accumulates 

 in the tissues, especially in the brain. 



(3) The amount of chloroform in blood which produces anaesthesia varies 

 with the rate of the induction of anaesthesia. 



Milligrammes of CHC1 3 per 

 Mins. 100 grammes of blood. 



2—3 60—70 

 5—8 44 

 Much slower 34, 35 



(4) The determinations of the amount of chloroform found in venous blood 

 after death by Nicloux is, according to Tissot, useless for a determination of 

 the lethal dose, for this is always less than what is found in arterial blood, 

 and when dogs are killed by the slow inhalation of 5, 6, 7, or 8 per cent, of 

 chloroform vapour the lethal figure for arterial blood varies between 48 and 

 67 milligrammes. A quantity as large as 160 milligrammes may be found 

 in blood before respiration stops. Such a large accumulation is impossible 

 with inhalation of 4 to 5 per cent, chloroform vapour, for with this amount 

 of chloroform it is impossible to raise the amount in arterial blood above 

 40 to 45 milligrammes per 100 grammes. 



(5) Anaesthesia can exist with a very low content in the blood, for instance, 

 29 milligrammes per 100. 



(6) There is no relation whatever between the proportion of chloroform in 

 the blood and the effects of the drug, for these are determined, not by the 

 absolute amount of chloroform present in blood, but by the quantity which 

 enters the central nervous system. The amount in this may equal, never 

 exceeds, and generally is much below that in the blood. 



(7) During recovery from anaesthesia it has been constantly proved that the 

 amount in venous blood exceeds that in the arterial. A study of the amount 

 of chloroform in arterial blood should be made during the induction of 

 anaesthesia and of the amount in venous blood during the disappearance of 

 this condition. 





Cessation of chloroform 

 administration immediately 

 after anaesthesia. 



45 minutes 

 later. 



• 2 hours 

 later. 



Arterial blood ... 

 Venous blood ... 



53 -2 

 48 -1 



5-8 

 7-7 







4-9 



The effect of chloroform upon the blood, which precipitates haemoglobin and 



