:)',{.) ELECTRICITY. 



of their flames carries off much of the electric 

 fluid. 



Lastly, the young electrician is cautioned not to 

 depend on first appearances in electricity. Anew 

 phenomenon may justly excite his curiosity. It is 

 laudable to remark it, and to pursue the hint; but 

 at the same time, even the doubtful assertion of a 

 new fact should never be made till after a number 

 of similar and concurring experiments. Electricity 

 is a science that often deceives the senses; and the 

 most experienced frequently finds himself mistaken 

 in things which perhaps he may have considered 

 before as the most certain. 



In many electrical experiments, it is very conve- 

 nient to have a method of determining, whether a 

 small degree of electricity be positive or negative : 

 and in using large batteries, it is a matter of con- 

 sequence to know how the charge advances, and of 

 what strength it is. Mr. Canton's balls are ex- 

 tremely useful for both these purposes. They are 

 made- of the pith of elder, turned perfectly glo- 

 bular, and suspended from the conductor by fine 

 threads. 



To understand the use of them, suppose ajar or 

 battery stands upon the table; to know whether 

 the inside be charged positively or negatively; pre- 

 sent the balls, and they are immediately attracted 

 by the wire, and diverge from one another. This 

 is common to both electricities ; and the greater 

 the distance to which the balls separate, and the 

 farther they repel one another, the higher is the 

 charge. To determine of what kind it is, rub a 

 small piece of glass against your hand or coat, 

 which will excite it positively, and then present it 

 to the balls in their diverging state. If it make 

 the balls converge, and consequently avoid the 



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