TV. AND REVIVED. 131 
‘quantity of fand. One of my friends, an emi. 
nent philofopher and an excellent microfcopical 
obferver, has uniformly obtained the fame refult in 
‘his experiments (1). The Abbé Roffredi, a good 
obferver, when incidentally fpeaking of the wheel 
animal in:the “fournal de Phyfique, by the Abbé 
Rozier, mentions the like phenomenon. 
To thefe, the following faéts may be added. 
if the fand containing «wheel animals is {pread 
out in fuch a manner that a confiderable quan- 
tity is in fome places, muchlefs in others, and 
very little in the reft, and the whole then moiften- 
ed ; in the firft.cafe, where it is plentiful, the re- 
wiving animals will be numerous; where it is 
more rare, fewer will recover: And, im-the laft 
cafe, very few, or fometimes none. If a dried 
portion of fand, which was thick before, ‘is {cat- 
tered very thin and moiftened, few wheelers will 
appear, though formerly numerous. Their refur- 
rection in a {mall quantity is uniformly later than 
where fand abounds; here it will-becomplete in 
four minutes: when there is little fand, refur- 
rection will require nine or eleven minutes, and 
fometimes more. 
Have the animals not reviving froma defed 
of fand, and refembling globules floating in the 
aater ; have they loft the refurgent faculty, or 
do they refume it on being fupplied with their 
L2 native 
41) I) Padre D, Carlo Giufeppe Campi di Milane. 
