New Outlines of Chemical Philosophy. 



243 



7/>2 



leaf of dimensions equal 

 to the former, suspended 

 from the lower end of the 

 wire u/r. osyz is a piece 

 of thick nnisic wire, one 

 end of which is fixed into 

 a peg of hard wood in- 

 serted into the base of 

 the instrument at X ; but 

 the rest of the wire is de- 

 tached, and vibrates freely 

 with the least force im- 

 pressed upon it. The 

 glass cylinder, standing in 

 a groove turned out of 

 the foot of the instru- 

 ment, protects tlie pen- 

 dulums c?p and rq from 

 being disturbed by cur- 

 rents of air. 



The thermometer tube 

 al and one end of the 

 wire xy are fixed into 

 the base on the outside of 

 the glass cylinder : the 

 other end of the wire yz 

 and pendulums are sus- 

 pended within it. 



To the lower ends of 

 the pendulimis p and cj 

 two pieces of thin wire 

 are attached, of the forms 

 represented in fig. 2. 



Exp. 1. An electric column being laid upon two insulating 

 stands in an horizontal position, an electrometer placed in con- 

 tact with the zinc end of it exhibited only a few degrees of elec- 

 tricity, nor was any greater effect produced on the electrometer 

 when it was applied to the copper end. Hence it appears that 

 the column contains very little electricity in an insulated state. 



Exp. 2. The electrometer remaining in contact with the cop- 

 per end of the column, as soon as a communication was made 

 between the zinc end and the earth by means of a piece of wiie, 

 one end of which stood upon the table, with its other end in 

 contact with the end of the column, the leaves of the electro- 

 meter diverged to an angle of thirty degrees. This electrome- 

 ter being bet aside, and another eijually sensible placed in con- 

 Q 2 tact 



