378 PELTIER ON THE CAUSES OF THE 
ceived with repugnance, whatever its merits may be, because it 
forces upon us an effort of the mind, which the faith we had in 
the affirmations of the ancient theory relieved us from. 
4. Ina special work, I will state why I can neither admit the 
two fluids of Dufay nor Franklin’s single fluid. I will then 
show that the cause of the electric phenomena is like those of 
light and heat, a modification of the universal fluid which fills 
space. I will indicate what is the modification which it receives, 
in order to produce these new manifestations; a modification 
quite different from those of light and heat; then only shall I 
be able to propose a nomenclature appropriate to the true 
causes; but till then I cannot dispense with the use of the 
customary language which has been created for theories which 
everywhere totter, and which have no support in facts. In the 
infancy of a science, as many forces are created as there are phe- 
nomena to explain, as in mechanics a motive force was given 
to each effect which we desired to produce; but progress in the 
one science as well as the other, shows this multiplication of 
forces to be unnecessary, and reduces the different effects to a 
single force. The terms vitreous and resinous, positive and 
negative, which IJ am still obliged to use, do not present to my 
mind any of the meanings which the theories from which they 
have originated attribute to them; they will have, in my opinion, 
no other value than that of indicating the different degrees of 
the same state, setting out from a point of equilibrium, deprived 
of electric manifestation. This is not the time to prove in de- 
tail why I consider the resinous state as the real electric phe- 
nomenon, and why the vitreous state is but the absence or dimi- — 
nution of it. Without entering into these considerations in the — 
present memoir, we shall see that all the phaenomena which will © 
occupy our attention agree in this, that by admitting this asser- 
tion the natural phenomena arrange and transform themselves 
without effort. We shall employ the words resinous and vitre- 
ous in preference, as the least significant, meaning by the first 
a more resinous tension than the point of equilibrium, and by 
the other a /ess resinous tension than that which this same point 
possessed. 
5. I will again mention what I have already said several times ; 
it is that our instruments for measuring electricity only indicate 
the differences of the same condition, and not contrary condi- 
tions, nor absolute quantities. Their function is limited to tell, 
