r 250 j 



of ufe to. them- to be informed, that I kept theire 

 without, any difficulty in glafs receivers, open at- 

 the top and bottom, and having a quantity of 

 paper, or tow, in- the infide, which mould be 

 changed every three or four days; when it will 

 be moll convenient alfo to change the veflel, and; 

 wafh it. But they muff 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 melf over the kitchrn 

 fire place, where,, as it is ufual in Yorkmire, the 

 fire never goes out ; fo that the heat* varies very 

 little; and I find it. to be at a.medium about 70 

 degrees of Fahrenheit's thermometer. When they 

 had been, made to pafs through the water, as they 

 necefiarily mud be, in order to a change of air, 

 they require, and will bear a very confiderable dej- 

 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 leveral times, they would" never t afire 

 it; and yet they continued in perfect 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 

 almoft in pieces, though there was plenty of 

 provilions for both of them. 



The apparatus with which the principal of 

 the preceding experiments were made is exceed- 

 ingly fimple, and cheap. The drawing annexed 

 (Tab. IX.) exhibits a view of every thing that is 

 mod important in ft. 



A is 



