Theories and Experiments 205 



case they have been kept in the vacuum for some time after the death 

 of the animal. That proves that this death should not be attributed 

 to the contraction of the lungs .... Perhaps the lungs do not become 

 denser in the vacuum, and seem so when they are withdrawn only 

 on account of the pressure of the outer air, which then begins to 

 act upon them. Besides, when all the other parts of the body swell in 

 the vacuum, it is not clear why the lungs should be the only excep- 

 tion. 



We see that Veratti is far from being satisfied with the result 

 of the experiments of the Dutch physicists. However, he does not 

 take sides definitely, although he is inclined towards the opinion 

 of Borelli. 



In another memoir 12 which he devotes to the study of asphyxia 

 in closed vessels, he makes an observation, mistaken to be sure, 

 which shows how complex these questions seemed to him: 



None of the animals which die in the receivers (confined air) 

 have convulsions, as always happen to those which die under the 

 receiver of the pneumatic machine; which proves that the cause which 

 kills animals in confined air is very different from that which kills 

 them in a vacuum. 



We are really much surprised to see, after that, that in the 

 explanation of the death of the enclosed animals he gives an im- 

 portant role to "the destruction of the elasticity of the air, proved 

 by his experiments", that is, to a decrease in pressure of a few 

 millimeters of mercury. 



Another Italian, J. Fr. Cigna, 13 shortly after, carried on research 

 of the same type on death in closed vessels. But he was the first 

 to have the idea of studying what would happen to animals kept 

 until death in closed receivers, in air of different degrees of rare- 

 faction. 



He used a bottle containing "about 50 pounds of water". In it 

 he placed a sparrow, then pumped out the air in two minutes to 

 a decompression of 16 inches, 10 lines: 



The animal vomited at the beginning, went through a few con- 

 vulsions, then seemed in fairly good condition for a few instants. Its 

 respiration at first was shallow and rapid; it became still more so 

 afterwards; soon it was rapid and deep, and finally deep and slow; 

 then came convulsions which ended its life. The mercury had risen 

 little by little in the siphon, so that at the time of the animal's death its 

 height had increased about 4V 2 lines. Counting from the moment when 

 communication of the tube with the pump had been cut off, the 

 sparrow had lived 35 minutes .... 



After washing the bottle, I placed another sparrow in it; I pumped 

 out the air so that the mercury rose in the siphon only to 13 inches, 

 5 lines, and I cut off the communication of the bottles with the pump. 



