64 Existence of Radicals in the Amphide Salts disproved. 
can be drawn, still it has been found advantageous to classify 
them to the best of our power. Accordingly it appears to me 
expedient, in the first place, to distinguish elements (or those 
compounds which act like them) according to their electro-chem- 
ical relations to each other, or their habitudes with the voltaic 
electrodes. Consistently, chemists have tacitly adopted the plan 
of treating the compounds formed by electro-negative elements 
with anions, as acids; those formed with cathions, as bases ; 
while the combinations formed by the union of such acids and 
bases have been considered as simple salts. ‘Thus four classes 
are constituted, consisting of electro-negative elements, of acids, 
bases, and single salts, while, by the union of the latter, a fifth 
class of double salts is formed. Whether the words acid, base, 
and salt, be adhered to, objectionable as they are in some re- 
spects, and especially the latter, or some others be contrived, it 
would seem to me disadvantageous to merge them in one name, 
pursuant to the views of the advocates of salt radicals, as stated 
by Gregory in his edition of 'Turner’s Chemistry, 572. 
38. The objection, that not being electrolytes the relation of 
acids and bases to the voltaic electrodes cannot be discovered, is 
easily remedied; since, on the union of a common ingredient 
with an anion and a cathion, there cannot be any doubt that the 
resulting compounds will have the same electro-chemical relation 
as their respective heterogeneous ingredients; so that, with the 
anion, an acid or electro-negative body will be formed ; with the 
cathion, a base or electro-positive body. Moreover, as respects 
organic compounds which cannot be subjected to the electrolytic 
test, whatever saturates an inorganic acid must be a base, and 
whatever saturates an inorganic base must be an acid. 
39. The word salt, I have shown, is almost destitute of utility, 
from the impossibility of defining it, and the amplitude of its 
meaning. A word that means every thing, is nearly as useless 
as that which means nothing. 
40. As respects the three phosphates of water, PO*+HO, 
PO*+2HO, PO’-+3HO, the argument used by Dr. Kane cuts 
both ways; although, by its employer, only that edge is noticed 
which suits his own purpose. It is alleged that the difference of 
properties, in these phosphates, is totally inexplicable upon the 
idea of three degrees of ‘hydration ;” but that all difficulty van- 
ishes, When they are considered as three different compound salt 
