iV. _ AND REVIVED. 153 
logy to wheel animals, as the animalcula of infu- 
fions. It has been proved that thefe are produc- 
ed in vacuo. This feems an effeCtual method 
for preventing the refurreCtion of wheel animals, 
though’ we cannot deny that their refurrection is 
facilitated by the influence of the air. The prin- 
cipal refults of repeated experiments, are, 1. 
Wheel animals revive fooner and in greater num- 
ber in the open air than in vacuo. 2. Thofe that 
do not revive in vacuo, recover when. put in the 
open air. 
However much air may promote the refurrec. 
tion of wheel animals, it is abfolutely neceflary 
for the prefervation of their lives. When they re-~ 
vive in vacuo, or are put into an exhaufted re- 
ceiver, they die in a few days. 
If wheel animals did revive in vacuo, though 
not fo fuccefsfully as in the open air, it was very 
reafonable to fuppofe they would. alfo revive in 
confined air, though it is one method of prevent- 
ing the developement and of occafioning the de- 
ftruction of other animals confined in very {mal} 
veflels. I fealed up fome with wet fand in veffels : 
they always revived very foon, and in abun- 
dance: they have even lived long, though, from 
the extreme fmallinefs of the vefiels, there could 
be very little air. 
Wheel animals fuffer from many fluids what 
they do not fuffer from privation of air, or from 
air 
