[ i9 a 1 
cleaned and fulphured, or that were of a 
more fubftantial make, he found that the 
power of cohefion was increafed to a con- 
flderable degree. Thus, under thefe cir- 
cumftances, he has been able to make the 
black flocking and the white, when the 
rough fides of each were put together# 
raife (the half gauze) from twenty to 
forty, and of fpun filk, from forty to 
ninety times its own weight. Phil. Tranf. 
Anno. 1759, vol. li. p. 50. 
The author conjectured from this mo¬ 
ment, that the fame effeCt, and perhaps a 
greater one might take place between two 
plates of glafs, and fome time afterwards 
he took an opportunity of putting this 
idea to the proof. 
He took two panes of common window 
glafs, and covered one of the tides of each 
with thin tin-foil, leaving a fpace of near an 
inch from the edges uncovered. He warmed 
them a little at the fire, and applying the 
two 
