1884.] 
Significant Nomenclature. 473 
significant names on account of their length, and an objec- 
tion on this ground applies especially to the names used in 
Organic Chemistry, many of which are certainly somewhat 
cumbersome. Dinitromonobromobenzene is a long word, 
and it is not very pretty or euphonious, but it clearly indi- 
cates what the compound is (isomers excepted) ; and the 
gain of such clear indication is enormous. The great 
beauty and utility of these long names in Organic Chemistry 
is that they distinctly state to a chemist, who may never 
have heard of the compound, exactly what it is. There 
may or may not be such a substance existing as amylethyl- 
methylphenylammonium hydroxide : I never read of it, but 
if I met with the above name I would have no difficulty in 
writing the formula, and I would also have a general idea 
as to its properties and probable reactions. It is possible to 
make fun of monstrosities like the above, and occasionally a 
feeble jokelet appears in the comic papers based on the long 
names in Organic Chemistry ; but scientific nomenclature 
is meant for scientific men, who need not care if outsiders 
try to veil their ignorance by endeavouring to raise a laugh. 
One objection to significant names in this science is that a 
compound not unfrequently has two or even more names, 
according to the view taken of it. Thus C 6 H 5 C 1 may either 
be looked upon as a chloride of the positive radical phenyl, 
or as a substituted derivative of benzene ; in the one case 
it is termed phenyl chloride, in the other monochlorbenzene. 
Similarly the compound C 6 H 5 NH 2 may be called phenyl- 
amine or amidobenzene, according as it is regarded as 
derived from ammonia by replacing an atom of hydrogen 
by phenyl, or from benzene by replacing a hydrogen atom 
by amidogen. These double names do not cause any real 
inconvenience to chemists, but they doubtless perplex 
learners. 
Occasionally theories change, — that is, the method of 
classification alters, — and this necessitates some variation 
in significant names : this variation causes, or at any rate 
tends to cause, confusion, and its existence — or at least the 
liability to its existence — is rightly put forward by Mr. 
Fernseed as an argument against significant names. There 
is certainly some force in this contention, but it scarcely 
outweighs the general utility of significant names, and the 
instance quoted as to a change in a significant name ren- 
dered necessary by a change in theory is not very apropos. 
The compound Na 2 S 2 0 3 had been in the first instance 
assigned an erroneous appellation. Sodium sulphite is 
VGL. VI. (THIRD SERIES). 2 I 
