Propagation of the Electric Force. 259 



RESIN. 



At the distance of five inches, one spark passed in one revolution of the 

 plate ; at the distance of two feet, one spark in two revolutions ; at the distance 

 of four feet, one spark in two and three-fourth revolutions. 



These latter substances begin to conduct when in the viscid state, and the 

 conducting power Increases up to the boiling point. 



SOURCE OF ELECTRICAL DEVELOPMENT. 



Before reconsidering the source of electrical development, I shall briefly 

 mention the arguments which may be brought forward against the emission, and 

 in favour of the vibratory theory, the former supposing a transference of elec- 

 tricity from particle to particle, the latter assuming that the atoms of matter 

 are encircled with ethereal atmospheres, the atoms of which can oscillate within 

 certain distances. The arguments in favour of this latter theory, independent 

 of such as the mathematician may bring forward, rest upon the hypothesis 

 proposed by Sir H. Davy,* " which, after a lapse of twenty years, continued, 

 as it was in the beginning, to be the guide and foundation of all his re- 

 searches;" a theory now almost universally received as established — that chemical 

 affinity is an electrical phenomenon, and that the entire subject of chemistry 

 is an illustration of that primary law of electricity, the attraction of oppositely 

 electrical bodies. If the electric forces which cause the attraction of bodies be 

 definite, as they are, being their atomic numbers, how can this be consistent with 

 a theory which supposes that the electricity leaves the particles, allowing them at 

 one moment to contain more electricity than at another, and, consequently, a 

 higher affinity, and a different atomic number ? 



When two atoms are brought into contact, their electrical ethers, being 

 disturbed, cause a disturbance to take place in the electrical ethers of adjacent 

 atoms, which disturbance should increase until it arrives at a maximum, when 

 combination takes place. The same may be said of the compound atoms or 

 molecules, of the compound molecules or particles, and of the compound par- 

 ticles or bodies en masse ; and that such a development of electricity by contact 

 of the latter does take place, the original experiments of Volta, together with 



• Bakerian Lecture, 1807-1826. 



2 l2 



