S02 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
[April 8, 1871. 
the many. Afterwards it was felt that the multi¬ 
plication of chemical substances by discovery ren¬ 
dered adherence to a trivial and arbitrary nomen¬ 
clature impossible, and the adoption of Lavoisier’s 
scientific plan imperative. Lavoisier got the world 
out of a difficulty, not placed it in one, when he in¬ 
troduced the principle of scientific nomenclature. 
Up to 1807 no necessity arose for interfering with 
the nomenclature of Lavoisier; but in that and the 
following year Davy made his brilliant researches 
on the alkalies and alkaline earths, discovered that 
potash, soda, baryta, strontia and lime were not 
elements, as previously had been supposed, but that 
the true basylous radicals of the so-called compounds 
of potash, soda, baryta, strontia and lime were me¬ 
tals—to which were given the names potassium, 
sodium, barium, strontium and calcium. Thence¬ 
forward the old names potash, soda, baryta, strontia, 
lime, were used to designate the oxides of the new 
metals. Then at once there arose a dilemma in re¬ 
gard to nomenclature. The names of all the salts of 
Davy’s metals were no longer consistent with the 
names of the salts of all other metals. While on 
the one hand the names ‘ sulphate of copper ’ and 
* sulphate of iron ’ distinctly expressed the com¬ 
pounds formed by the union of metallic * copper ’ or 
metallic ‘ iron ’ with a common acidulous group of 
elements, represented by the word ‘ sulphate,’ the 
names ‘ sulphate of soda ’ and 4 sulphate ot lime ’ as 
distinctly expressed compounds formed by the union 
of oxide of sodium and oxide of calcium with a 
common acidulous radical still indicated by the 
word 4 sulphate,’ but not having the same composi¬ 
tion as (having less oxygen than) the similar acidu¬ 
lous radical united with the copper and the iron. It 
was felt that either such words as sulphate, nitrate 
and carbonate must each have two significations, 
and the salts of the alkalies and alkaline earths be 
considered as compounds of oxides of metals, and all 
other salts (sulphate of iron, etc.) as compounds of 
metals, or such words (sulphate, nitrate, carbonate, 
etc.) must have a common (though an altered) signi¬ 
fication, and all oxygen salts be considered as com¬ 
pounds of oxides of metals. Davy, supported after¬ 
wards by Dulong, Clark, Graham, Liebig and Daniell, 
suggested that all metallic salts were composed of me¬ 
tal alone on the basylous side, and a distinct radical 
on the acidulous side. Unfortunately, however, ac¬ 
curate knowledge of constitution -was included in 
this idea; even definite names being proposed for 
the said acidulous radicals. Thus blue vitriol was 
termed oxysulphionide of copper (Daniell), sulpliat- 
oxide of copper (Graham) and sulplianide of copper 
(Otto). Many other objections to the theory arose, 
and hence salts came to be regarded as compounds 
of oxides of metals with certain acidulous radicals 
(now known as anhydrides). But the followers of 
applied chemistry never took kindly to the nomen¬ 
clature ; such names as sulphate of oxide of iron, 
nitrate of oxide of silver, acetate of oxide of lead, got 
shortened to sulphate of iron, nitrate of silver, ace¬ 
tate of lead ; a matter of no great moment to any one 
who had become a chemist, but of considerable im¬ 
portance to every one learning to be a chemist. The 
names acetate of lead, iodide of lead, etc., logically 
planted in the mind the impression that the com¬ 
pounds were formed of lead with the radical of ace¬ 
tates and lead with the radical of iodides,—a na¬ 
tural idea, which had to be unlearned, and by con¬ 
siderable effort of memory a mere conventional one 
put in its place, namely, that certain acidulous radi¬ 
cals (iodine, sulphur, etc.) combined with metals, 
while certain others (anhydrides, formerly called 
acids) with oxides of metals. Again, that a yellow 
granular precipitate, caused by the addition of per- 
cliloride of platinum to a liquid sometimes indicated 
potassium and sometimes potash, or that a certain 
black coloration sometimes indicated lead and 
sometimes oxide of lead, were illogical statements 
against which the mind naturally rebelled. It is 
true an explanation was afforded of such anomalies 
by the assumption that even haloid salts (such as 
iodide of potassium) on dissolving in water became 
true salts of oxides of metals (hydriodate of potash); 
but weighty arguments were adducible against this 
hypothesis. In short, no theory of the constitution 
of salts was offered, or has yet been offered, which 
satisfactorily explains and harmonizes all known 
facts respecting salts. Hence, when a very few 
years ago chemists were led by irresistible argu¬ 
ments and stubborn facts to double many of the old 
atomic weights, an opportunity of abandoning exist¬ 
ing constitutional theories then presented itself, and 
was by common consent accepted. The exertions of 
Dumas, Laurent and Gerliardt bore fruit. The 
dualistic idea of salts being formed of an acidulous 
radical with the oxide of a metal, and the not less 
binary notion of their being composed of a distinct 
acidulous radical united with a metal, were re¬ 
nounced, and hypothesis altogether rejected, or, at 
all events, restricted to the idea of oneness. These 
views were, of course, accompanied by a commen¬ 
surate alteration in chemical notation and nomen¬ 
clature. Blue vitriol no longer being considered to 
be the sulphate of the oxide of copper, as shown in 
the formula CuO,S0 3 , nor even to have the binary 
constitution implied in the formula Cu, S0 4 , but to 
be a structure per se , or, at least, one whose detail of 
constitution was unknown,—it became necessary to 
devise for it and all such salts, a notation and no¬ 
menclature which should be consistent with the 
unitary idea. Strictly speaking, this was impos¬ 
sible. The relationship, nay, the absolute identity 
of the constituent radicals in whole classes of salts 
demanded fair representation in notation and nomen¬ 
clature, a result fatal to pure unitary ideas. Thus, 
the unquestioned relationship of the cupreous com¬ 
pounds to each other demanded the employment of 
the word ‘ copper ’ in their names and the symbol Cu 
in their formulae; while the unquestioned relation¬ 
ship of salts containing the elements which occur in 
the non-cupreous portion of blue vitriol demanded the 
employment of the word “ sulphate ” in their names 
and the symbols S0 4 in their formulae, and with the 
employment of such names and such formulae the 
binary idea is difficult to repress. At the same time 
all are agreed that the unqualified assumption of 
knowledge of chemical constitution involved in the 
old binary theories is wrong, hence professedly bi¬ 
nary systems of notation and nomenclature must be 
relinquished ; the names sulphate of oxide of copper, 
with its formula CuO,S0 3 , and sulphate of oxide of 
magnesium (or sulphate of magnesia), with its for¬ 
mula MgO,SO a , must be given up for sulphate of 
copper CuS0 4 (or copper sulphate or cupric sul¬ 
phate), and sulphate of magnesium MgS0 4 (or mag¬ 
nesium sulphate). Such names and formulae suffi¬ 
ciently exhibit unquestioned relationships, while they 
include the least possible amount of theory. 
Chemical Notation .—I would offer a few addi- 
