546 PHILOSOPHICAL TRANSACTIONS. [aNNO 1742. 



Some further Observations concerning Electricity. By J. T. Desaguliers, LL. D. 



F.R.S. N°462, p. 14. 



Electrics per se, which Dr. D. has heretofore defined, bodies in which an 

 electrical virtue may be raised by some action on them, such as rubbing, patting, 

 warming, &c. are reduced to a non-electric state by being in contact with 

 non-electric bodies, especially water, which is the greatest non-electric, even 

 when it becomes vapour. 



A non-electric, which though it cannot be made electrical by any action 

 upon it, receives electricity from an excited electrical body ; but does not retain 

 it while it touches any other non- electrical body. An electric per se, when it 

 is become non-electrical, differs from the non-electric per se in this ; that it 

 may be so restored to electricity, by applying a rubbed tube to it, as to repel 

 all other electrics of the same kind of electricity as the tube ; till it meets 

 with some non-electric body, which brings it back to non-electricity, or at least 

 to such a languid state, that its electricity is scarcely perceptible. 



The electricity may be also restored in the same manner by wax, &c. But 

 in both cases, an electric body, in a languid state, cannot be restored to elec- 

 tricity while it adheres to a non -electric per se. 



Experiments to illustrate these assertions. — From an horizontal cat-gut, which 

 is an electric per se, as most animal substances are, he suspended two feathers, 

 the one by a thread, and the other by a silk, about 2 feet long each : then ap- 

 plying the rubbed tube to the feather hanging by the silk, which silk is an 

 electric per se, the feather came to the tube, and stuck to it, as all non- 

 electric bodies do, till it was so impregnated with the virtue from the tube, as 

 to come out of its languid state, and become strongly electrical ; which ap- 

 peared by its flying from the tube, and being repelled as often as the tube was 

 brought near it ; till it had touched some non-electric body, or was left so long 

 as to imbibe the moist particles floating in the air ; by which it became non- 

 electric, and was again attracted by the tube. 



On applying the tube to the other feather that hung by the thread, which, 

 like most vegetable substances, is generally non-electric per se, the feather was 

 constantly attracted, and never repelled ; because the virtue communicated 

 from the tube to the feather, lost itself along the thread ; which would have 

 been retained by the feather, if it had floated in dry air, or been suspended by 

 an electric body. 



..vThese properties of electric bodies show the reason of that phenomenon, by 

 which a rubbed tube, after having attracted a feather, repels and chases it about 



