[ 2 5 ° ] 
of ufe to them to be informed, that I kept them 
without any difficulty in glafs receivers, open at 
the top and bottom, and having a quantity of 
paper, vor tow, in the infide, which ffiould be 
changed every three or four days; when it will 
be moft convenient alfo to change the veflel, and 
waffi it. But they mud: be kept in a pretty exact 
temperature, for either much heat or much cold 
kills them prefently. The place in which I have 
generally kept them is a ffielf over the kitchin. 
f re place, where, as it is ufual in Yorkffiire, the 
fire never goes out ; fo that the heat varies very 
little; and I find it to be at a medium about yo 
degrees of Fahrenheit’s thermometer. When they 
had been made to pafs through the water, as they 
neceflarily mud; be, in order to a change of air, 
they require, and will bear a very confiderable de- 
gree of heat, to warm and dry them. 
1 found, to my great furprize, in the courfe of 
thefe experiments, that mice will live intirely 
without water; for though I have kept fome of 
them for three or four months, and have, offered' 
them water feveral times, they would never tafle 
it ; and yet they continued in perfeft health and 
vigour. Two or three of them will live very 
peaceably together in the fame veflel ; though I 
had one inftance of’ one moufe tearing another 
almofl: in pieces, though there was plenty of 
provifions for both of them. 
The apparatus with which the principal of 
the preceding experiments were made is exceed- 
ingly Ample, and cheap. The drawing annexed 
(Tab. IX.) exhibits a view of every thing that is 
mofl important in it. 
A is- 
