90 Sir W. Snow Harris’s Researches in Statical Electricity. 
nished. The experiment with an electrified hollow globe there- 
fore appears to have been expressed in very inexact terms, and 
the phenomenon of the exclusive appearance of the charge upon 
the exterior surface somewhat misapprehended. 
12. It follows from these demonstrable conditions of elec- 
trical charge, that a stratum of what may be termed electrical 
particles must always necessarily exist upon the surfaces of a 
charged conductor, as is clearly demonstrable by experiment; and 
the electrical agency, whatever it be, penetrates to a greater or less 
degree the substance of the air itself, or other dialectric medium 
in contact with the conducting surface, as is well shown in Fara- 
day’s most comprehensive researches (1245). This is really the 
acceptation of the term electrical atmosphere ; a term correctly 
applied by the celebrated Volta, who most thoroughly compre- 
hended the practical nature of electrical force, notwithstanding 
that his power of rigorous thought has been questioned, and his 
theoretical views of electricity rather severely remarked on by an 
eminent writer not altogether unbiassed by theoretical opinion, 
and evidently not a little impatient of dissent*. That Volta was 
most perfectly correct in attributing the phenomena of charged 
electrical conductors to the presence of electrical atmospheres 
surrounding them, taken in the sense in which I have just ex- 
plained the term, is absolutely demonstrable by the most conclu- 
sive experiments : we remove the metal, and there remains the 
charged stratum; in other words, the atmosphere of electrical par- 
ticles, as it may be termed, entirely without and independent of it. 
13. The electrical stratum thus found to exist on electrified con- 
ductors appears firmly held to the surface by attractive force, and 
is inseparable from it by movement of the body. Franklin whirled 
a charged ball attached to a silk cord many times round in the air 
and with great velocity, still the ball retained its charget+. An 
electrified conductor, therefore, when transferred from one place 
to another, may be supposed to ¢arry the electrical stratum along 
with it, just as the metallic coating of charged glass would do. 
It is true that the term electrical atmosphere has been occasion- 
ally used in a vague and unsatisfactory sense, and has hence been 
justly discountenanced by many eminent physicists and mathe- 
maticians. When taken, however, in the sense in which J have 
applied it as expressive of a demonstrable fact, the question 
assumes quite another form. Volta, therefore, in referring the 
phenomena of electrical attraction and repulsion, and the opera- 
tion of electrified bodies generally on each other, to the imme- 
diate action of the electrical particles themselves held firmly on 
* Bibliotheque Universelle, article ‘ Volta.’ 
+ If we charge a plate of glass through plane moveable coatings of gilded 
wood, the coatings will adhere to the glass. 
