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



calculated and theoretical values found when working with 4 and 5 milli- 

 grammes of chloroform in 100 grammes of blood are due to accidental 

 coincidence, more especially when we remember that the analytical process 

 used involves distillation and subsequent saponification with alcoholic potash. 

 We would also urge that even if it be granted as possible to estimate exactly 

 by this method amounts of chloroform mixed with blood in vitro, the same 

 accuracy cannot be expected with chloroform which has been introduced into 

 the blood by the physiological process of inhalation ; at the same time we must 

 admit that his figures do not greatly differ from those in our experiments. 

 The results obtained by Mcloux show for dogs : — 



(1) That the anaesthetic dose varies for different animals. 



(2) The amount in the arterial blood when anaesthesia is induced is about 

 50 milligrammes per 100 grammes of blood (confirmatory of Grehant's results). 

 In a dog weighing 18 kilogrammes, 58 5 milligrammes were found 60 minutes 

 after commencement of administration, in another weighing 9 - 3 kilogrammes 

 it was 47 milligrammes 33 minutes after the commencement of administration. 



(3) The lethal dose in venous blood may be 70, 69, or 73 milligrammes per 

 100 grammes of blood. 



(4) During the pre-anaesthetic period the intake of chloroform is rapid 

 even with a low percentage of chloroform in the inspired air. Thus, within 

 three minutes 56 milligrammes were found with a high percentage of 

 chloroform in the air, and 55"5 milligrammes at the end of 32 minutes with 

 a small percentage of chloroform. 



(5) The differences between amounts of chloroform in arterial blood with 

 an anaesthetic and lethal dose are small. 



Anaesthetic dose. Lethal dose. 



Milligrammes per 100 grammes. Milligrammes per 100 grammes. 

 54 70 

 57 64 

 57 69 



An examination of Nicloux's figures, however, shows that in some cases the 

 lethal dose was less than the anaesthetic one for the same dogs, thus — 



Anaesthetic dose. Lethal dose. 



Milligrammes per 100 grammes. Milligrammes per 100 grammes. 



47 42 



48 41 



This is possibly due to alterations in the rate and depth of respiration. 

 The weights of the dogs show that there is no relation between weight and 

 an anaesthetic dose of chloroform — 



