fame Electrical Experiments . 
5 , 3 - 
EXPERIMENTS MADE WITH A GLASS TUBE HERMETI- 
CALLY SEALED, AND HAVING SOME QUICKSILVER 
INCLOSED IN ITS CAVITY. 
I N making fome experiments rather foreign to elec- 
tricity, it occurred to me, that when I agitated fome 
quickiilver in a glafs tube hermetically fealed, and in 
which the air was very much rarefied, it contracted a 
very fenfible quantity of electricity ; which however was 
not conftant, nor, as I firft thought, in proportion to the 
agitation of the quickiilver. Being defirous of afcertain- 
ing the properties of this tube, I conftrudted feveral of 
them, and, as accurately as I could, obferved their pro- 
perties ; but as they all agreed with regard to the chief 
points, I lhall only defcribe one, which is the bed: I have 
yet made. 
This tube is two feet and feven inches long, and about 
four tenths of an inch in diameter: the quickiilver in 
it may be about three quarters of an ounce, and to ex- 
haull it of air, I clofed it whilft the quickiilver was boil- 
ing in its oppolite end. 
Before I ufe this inllrument I warm it a little and 
clean it; then holding it nearly horizontally, I let the 
quickiilver in it run from one end of the tube to the- 
other* 
