626 Mr. nairne’s Account of 
pump was then worked, and the barometer-gage indi- 
cated a degree of exhauftion of nearly 300 ; but on the 
admiffion of the air the pear-gage indicated a degree of 
exhauftion of 4000, 
EXPERIMENT V. 
The piece of leather being taken out, the pump was 
then worked, and the degree of exhauftion appeared by 
both the barometer and pear-gages to be about 600, as 
in the third experiment. 
EXPERIMENT VI. 
A cylinder made of a piece of box wood (which I had 
kept by me for more than a year) one inch in diameter 
and three inches in length, was put into the receiver 
(this piece of wood was of the fame kind as that which 
was cemented to the foot of the glafs cup ufed in the firft 
and fecond experiments) the pump was then worked, 
and the degree of exhauftion appeared by the barometer- 
gage to be 300, but by the pear-gage 16,000. 
Thele experiments have often been repeated, but the 
refult was leldom the fame. When leather foaked in oil 
and tallow has been put into the receiver, the pear-gage 
has fometimes indicated a degree of exhauftion of 
2O3O00, 
