On the absolute Charge of Matter. 285 



be charged with one electric force independently of the other y 

 in the least degree, either in a sensible or latent state? 



1 1 70. The beautiful experiments of Coulomb upon the 

 equality of action of conductors^ whatever their substance, and 

 the residence of all the electricity upon their surfaces*, are 

 sufficient, if properly viewed, to prove that conductors cannot 

 he bodily charged; and as yet no means of communicating 

 electricity to a conductor so as to relate its particles to one 

 electricity, and not at the same time to the other in exactly 

 equal amount, has been discovered. 



1171. With regard to electrics or non-conductors, the con- 

 clusion does not at first seem so clear. They may easily be 

 electrified bodily, either by communication (1247.) or excite- 

 ment ; but being so charged, every case in succession, when 

 examined, came out to be a case of induction, and not of ab- 

 solute charge. Thus, glass within conductors could easily 

 have parts not in contact with the conductor brought into an 

 excited state ; but it was always found that a portion of the 

 inner surface of the conductor was in an opposite and equiva- 

 lent state, or that another part of the glass itself was in an 

 equally opposite state, an inductive charge and not an absolute 

 charge having been acquired. 



1172. Well-purified oil of turpentine, which I find to be 

 an excellent liquid insulator for most purposes, was put into 

 a metallic vessel, and, being insulated, was charged, sometimes 

 by contact of the metal with the electrical machine, and at 

 others by a wire dipping into the fluid within ; but whatever 

 the mode of communication, no electricity of one kind was re- 

 tained by the arrangement, except what appeared on the ex- 

 terior surface of the metal, that portion being there only by 

 an inductive action through the air around. When the oil of 

 turpentine was confined in glass vessels, there were at first 

 some appearances as if the fluid did receive an absolute charge 

 of electricity from the charging wire, but these were quickly 

 reduced to cases of common induction jointly through the 

 fluid, the glass, and the surrounding air. 



1173. I carried these experiments on with air to a very 

 great extent. I had a chamber built, being a cube of twelve 

 feet in the side. A slight cubical wooden frame was constructed, 

 and copper wire passed along and across it in various direc- 

 tions, so as to make the sides a large net-work, and then all 

 was covered in with paper, placed in close connexion with 

 the wires, and supplied in every direction with bands of tin- 

 foil, that the whole might be brought into good metallic com- 



• Mcmoires de I'Academie, 1786, pp. 67, 69, 72; 1787, p. 452. 



