\'OL. XLV.] PHILOSOPHICAL TRANSACTIONS, 453 



As this experiment was made, and the solution given on the other side of the 

 Atlantic Ocean, before this gentleman could possibly be acquainted with our hav- 

 ing observed the same fact here, and as he seems very conversant in this part of 

 Natural Philosophy, I take the liberty of laying before you his own words. 



" 1. A person standing on wax, and rubbing a tube, and another person on 

 wax drawing the fire; they will both of them, provided they do not stand as to 

 touch one another, appear to be electrised to a person standing on the floor; 

 that is, he will perceive a spark on approaching each of them with his knuckle. 

 2. But if the persons on wax touch one another during the exciting of the tube, 

 neither of them will appear to be electrised. 3. If they touch one another after 

 exciting the tube and drawing the fire as aforesaid, there will be a stronger spark 

 between them, than was between either of them and the person on the floor. 

 4. After such a strong spark neither of them discover any electricity. 



" These appearances we attempt to account for thus: we suppose that electrical 

 fire is a common element, of which every one of these 3 persons has his equal 

 share before any operation is begun with the tube, a, who stands on wax, and 

 rubs the tube, collects the electrical fire from himself into the glass ; and his 

 communication with the common stock being cut off by the wax, his body is 

 not again immediately supplied, b, who stands on wax likewise, passing his 

 knuckle along near the tube, receives the fire which was collected by the glass 

 from A; and his communication with the common stock being cut off", he re- 

 tains the additional quantity received. To c, standing on the floor, both appear 

 to be electrised : for he, having only the middle quantity of electrical fire, receives 

 a spark on approaching b, who has an over quantity, but gives on6 to a, who has 

 an under quantity. If a and b approach to touch each other, the spark is stronger; 

 because the difference between them is greater. After such touch, there is no 

 spark between either of them and c, because the electrical fire in all is reduced 

 to the original equality. If they touch while electrising, the equality is never 

 destroyed, the fire only circulating. Hence have arisen some new terms among 

 us. We say, b (and bodies alike circumstanced) is electrised positively ; a, nega- 

 tively; or rather, b is electrised plus, a, minus. And we daily in our experi- 

 ments electrise plus or minus, as we think proper. To electrise plus or minus, 

 no more needs be known than this ; that the parts of the tube or sphere that 

 are rubbed, do in the instant of the friction attract the electrical fire, and there- 

 fore take it from the thing rubbing. The same parts immediately, as the friction 

 on them ceases, are disposed to give the fire, they have received, to any body 

 that has less. Thus you may circulate it, as Mr. Watson has shown;* you 

 may also accumulate or subtract it, on or from any body, as you connect 



* See my Sequel, p 64. — Orig. 



