1906.] 



Chloroform in the Blood of Animals. 



439 



tion stage was very much higher in the second half of the experiment than in 

 the first. In connection with this experiment we would draw attention to 

 the results of the administration of chloroform recorded at the end of 

 Tables I and II. 



In the two following experiments we used dogs instead of cats. The 

 phenomena observed were similar to those in the case of cats, but the 

 percentages of chloroform found at the various stages were somewhat higher. 



Experiment 10. — For the purpose of this experiment a dog weighing 

 10 kilogrammes was selected, and chloroform was administered by means of 

 a Woulff's bottle, the temperature at the time being rather high — viz., 24° C, 

 so that the percentage of chloroform in the air inhaled was probably some- 

 what higher than in those other experiments in which a Woulff s bottle was 

 made use of. Blood samples were taken from the left carotid. The control 

 sample was taken as usual under light ether anaesthesia, but in this case an 

 extra sample of 10 c.c. was also withdrawn for another purpose. Chloroform 

 was then administered, and samples of blood were collected when the reflexes 

 had just gone and when the animal was deeply anaesthetised. At the latter 

 stage an extra 10-c.c. sample was also taken for another purpose. The 

 anaesthesia was then pushed by lowering the air inlet tube to the surface of 

 the chloroform, and a sample of blood withdrawn when respiration ceased. 

 The animal was now allowed to recover naturally, and samples were taken 

 when breathing commenced regularly and when reflexes began to reappear. 

 At the latter stage chloroform was again administered until the animal died, 

 when a sample of blood was taken from the left auricle of the heart and 

 analysed. The results of this experiment are recorded in Table X and 

 Curve F'. As in the case of cats, the colour of the blood followed closely the 

 percentage of chloroform in the blood. 



Experiment 11. — In this case a very vigorous dog, weighing 105 kilo- 

 grammes, was selected, and the blood was withdrawn from the right carotid. 

 The chloroform was administered from bags filled with mixtures of chloro- 

 form and air of known composition by the Dubois apparatus. The control 

 sample of blood was taken under light ether anaesthesia, and at the same time 

 & 10-c.c. sample for another purpose. Chloroform of 2-per-cent. strength was 

 then administered, and duplicate samples taken when the reflexes had just 

 gone. Ten minutes later another sample of blood was taken. At this stage 

 the strength of the anaesthetic was increased to 3 per cent., and a sample of 

 blood withdrawn eight minutes later. The strength of the chloroform was 

 then increased to 4'5 per cent., and nine minutes later a duplicate sample of 

 blood was withdrawn. Fourteen minutes later another sample was collected, 

 and the chloroform was cut off. At this stage respiration had not ceased, but 



VOL. LXXVIII. — B. 2 L 



