﻿104 Canadian Record of Science. 



The blood is so sensitive to carbonic oxide that so little 

 as 0.03% in the air can be shown (Bull. Soc. cheni. (6) 663) 

 when a solution of blood is brought thoroughly in contact 

 with a mixture containing carbonic oxide. 



The best way to bring a liquid in contact with a large 

 body of air or gas would be to have it circulate by means 

 of minute canals, using a pump to keep the current in 

 motion through the cell walls of a sponge, while the air 

 was continually changed by squeezing and relaxing the 

 sponge. We can find such a little machine in a very per- 

 fect form in the body of a small animal, the veins and 

 arteries constituting the canals, the pump being repre- 

 sented by the heart, and the sponge by the lungs. 



If we sacrifice a mouse as a martyr to science and 

 enclose him in a tight box containing air with a known 

 percentage of carbonic oxide, and kill him after 3 or 4 

 hours, we can detect the carbonic oxide absorbed by his 

 blood. 



A similar method is best suited to discovering whether 

 acetylene is absorbed by the ])lood. We might suspect 

 that this would be the case since the two gases have in 

 common the peculiar property of being absorbable by 

 solutions of subchloride of copper. 



Grehant (Comptes Eendus, 1895, XL, 565) made a care- 

 ful comparison of carbonic oxide and acetylene in respect 

 to their poisonous qualities upon dogs. He took care to 

 have 20^ oxygen always in his mixtures, so as to give it 

 the vital quality of air and not to kill his animals by 

 suffocation. He added 1^ carbonic oxide {i.e., enough 

 Paris gas (containing 7% CO) to give 1% carbonic oxide). 

 After 3 minutes the animal suftered ; after 10 minutes 

 the dog was very sick and his blood contained 27 volumes 

 per 100 of carbonic oxide. The dog would have soon 

 died if the experiment had been prolonged. 



In a mixture containing 20^ oxygen and 20^ acety- 

 lene a do^y breathed without incon\enience for 35 minutes. 



