564 Reviews. | July, 
which is least of all possible in a text-book, a selection on scientific 
grounds is no easy matter. There are, for example, advantages in a 
name which inyolves no hypothesis, such as caustic potash, prussic 
acid, aniline ; and there are advantages in a name which suggests to 
a chemist the generally received formula of the substance, such as 
hydrate of potassium, hydrocyanic acid, phenylamine. As chemical 
knowledge advances, bodies of more and more complex constitution, 
that is, containing in one molecule a greater number of atoms and 
susceptible of a greater variety of decompositions, are separated out 
from natural products and investigated, or are built up by the now 
systematic processes of chemical synthesis. These bodies we represent 
by formule, which indicate the number and kind of atoms composing 
their molecules, and suggest as far as possible their modes of formation 
and decomposition. Chemists have striven to make the language 
of chemistry keep pace with this increase in their knowledge and in 
the complexity of their formule. Probably the attempt must be given 
up. Itis impossible to compress into a name facts which a formula 
may convey, but which require sentences for their verbal expression. 
As a consequence of this attempt, chemical names have become 
sentences, and it is often shorter as well as clearer to write down the 
formula of a substance than to call it by its name. In the future no- 
menclature of chemistry we conccive that the formula of a substance 
will be its name, and that we shall no more expect to have a word 
corresponding to every formula than to have a name for every algebraic 
expression. These considerations, however, apply chiefly to organic 
chemistry. Where the formule of substances are simple, the interval 
is greater, so to say, between one substance and another, and it has 
not been difficult to apply to each a characteristic name composed of a 
moderate number of syllables. Almost the only innovation sanctioned 
by Dr. Apjohn is the use of the names carbonate of sodium, &c., in- 
stead of carbonate of soda, &c. It is to be hoped that this change by 
which the names of salts become uniform and free from theory may 
soon meet with general adoption. The old terms ‘oil of vitriol,’ 
‘muriatic acid,’ ‘barytes, ‘strontites,’ ‘barytic water, ‘water of 
ammonia, and others, to which Dr. Apjohn adheres, appear to us to 
have been deservedly superseded. Dr. Apjohn must pardon us for 
venturing one or two verbal criticisms. The name metaphosphoric 
acid does not mean ‘ phosphoric acid associated with something else 
(water), p. 3896, but changed, or—to illustrate this use of the pre- 
position—metamorphosed, phosphoric acid. ‘ Hexangular’ is a bad 
substitute for hexagonal, and such expressions as ‘per saltum’ and 
‘quam proximé’ have no advantage over their English equivalents. 
Graver objections attach in our opinion to expressions of another 
class still much in vogue among chemists. We mean the phrases, for 
they are nothing more, which represent as the cause of a phenomenon 
some hypothetical force or law, whose existence is merely an infer- 
ence—and, as we think, an unmeaning, unscientific inference—from 
the phenomenon itself. We still recognize under different guises the 
famous explanation of Moliére’s physician. “Why,” it was asked, 
“ does opium send aman to sleep?” ‘ Because,” answered the sage, “ it 
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