23 



Being anxious to know if It were possible to obtain 

 a complete consumption of the oxygen gas by means 

 of these worms, I endeavoured to bring it to the test, 

 by confining a greater or less number of them in com- 

 mon air. They were confined at the superior part of 

 the vessel, to keep them out of the fixed air, which 

 they produce in ratio to the oxygen destroyed. This 

 air, being specifically heavier than common air, will 

 necessarily descend to the bottom of the vessel. I ob- 

 served those animals died sooner at the bottom than 

 at the top of the vessel — owing to the fixed air pro- 

 duced during their confinement, which will hereafter 

 be shown to be very noxious to them. By these means 

 I was able to cause a great consumption of the oxygen 

 — but not completely. 



The weather was changeable during the time I 

 was making these experiments. I found that it may 

 be established as a law, that the death of these animals, 

 as to time, is in proportion to the temperature of the 

 air in which they are confined ; so that they die so 

 much the later as the temperature is diminished. In 

 the first case the oxygen disappears sooner than in the 

 second. Probably this law is applicable to all animals 

 that pass the winter in a state of torpor. The reason 

 is evident: These animals belong to the cold blooded 

 class ; we know that they are weakened by too low a 

 temperature, that they become benumbed and inani- 

 mate. We find also that the gentle stimulus of a mild 



