March 13, 1896.] 



SCIENCE. 



385 



POISONOUS QUALITIES OF GAS AND ACETYLENE. 



Continuing the comparison of common 

 gas and acetylene, let us see how the case 

 stands from a sanitary point of view. We 

 see reports in the newspapers of deaths and 

 attacks of illness from gas poisoning, the 

 dropping out during the night of the core 

 of a gas cock or a break in a pipe, would 

 often be an accident fatal for the inmate of 

 a small, close bed chamber. Recently per- 

 sons have been poisoned by a defect in the 

 gas main outside of their -houses. Work- 

 men are frequently made ill by a leak in the 

 gas mains while working in a trench, but 

 the officers of the ga,s companies state that 

 such accidents are very seldom fatal. 



There is no question then about the 

 poisonous qualities of common gas and par- 

 ticularly of water gas. Is the new illumi- 

 nant likely to be less dangerous ? 



The poisonous constituent of common 

 gas is carbonic oxide. London gas contains 

 3.2 to 7% ; Paris gas 7% ; Berlin gas 8% ; 

 Boston gas 26%. 



Formerly there was a legal limit of 10% , 

 which is now removed, and the introduction 

 of water gas has raised the percentage to 

 this very high and dangerous amount. 



Carbonic oxide is not irritating or corro- 

 sive, and it seems strange that a compound 

 so nearly allied to carbonic acid, which is 

 innocuous, should act as a rapid poison. 



The mode of action is this: Carbonic 

 oxide is absorbed and retained by the blood 

 in a way quite different from other gases. 

 It combines with the red corpuscles, and 

 the compound shows under the spectroscope 

 special absorption bands, which make the 

 recognition of its presence easy. 



Blood which has taken up a certain 

 quantity of carbonic oxide no longer is 

 capable of taking up oxygen in the lungs 

 and conveying it through the circulation, 

 and death by suifocation ensues, just as if 

 there were not enough oxygen to breathe. 



The blood is so sensitive to carbonic 



oxide that so little as 0.03 % in the air can 

 be shown (Bull. Soc. chem. (6) 663) when a 

 solution of blood is brought thoroughlj^ 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 bj' 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 hj 

 squeezing and relaxing the sponge. We can 

 find such a little machine in a very perfect 

 form in the body of a small animal, the 

 veins and arteries constituting the canals, 

 the pump being represented 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 con- 

 taining air with a known percentage of 

 carbonic oxide, and kill him after 3 or 4 

 hours, we can detect the carbonic oxjde ab- 

 sorbed by his blood. 



A similar method is best suited to dis- 

 covering whether acetylene is absorbed by 

 the blood. AVe 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 Rendus 1895, II., 565) 

 made a careful 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 suffoca- 

 tion. He added 1% carbonic oxide {i. e., 

 enough Paris gas (containing 7% CO) to 

 give 1 % carbonic oxide) . After 3 minutes 

 the animal suffered ; 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 



