53° 
NATURE 
[Oct. 1, 1885 
the use of terms about the meaning of which every one is agreed, 
and their mere etymological accuracy is, in view of this all- 
important consideration, of secondary importance. Asa metal 
rarely—if ever—forms more than two salifiable oxides, the ozs 
and 7c terminations generally suffice for purposes of distinction 
so far as the salts of metals are concerned. The practice of 
further employing these terminations in the case of acid-forming 
oxides does not lead to confusion, since these oxides are distin- 
guished by the name anhydride (or acid). Thus we have 
CrO Cr,03 CrO3 
Chromous oxide. Chromic oxide. Chromic anhydride, 
(Chromic acid.) 
Indifferent oxides have frequently been classified and named 
by regarding them as compounds of salifiable, with acid-forming 
oxides, Cr,O, being termed chromic chromate. For stages 
lower than ows, the prefixes Aygo and s#b are employed. 
Custom appears to haye restricted Ayo chiefly to acids and to acid- 
forming oxides, sé to salifiable and to indifferent oxides. With 
regard to the termination ows, the minor question arises, how far 
this termination ought to be written in the forms zows and 
cous. The answer is: as seldom as possible. ‘‘ Cupreous” 
has generally given way to ‘‘cuprous”; no one writes 
‘“chromious” (although the name of the metal is ‘‘ chrom- 
ium”); and there is no reason why such names as ‘‘ ruthenious ”’ 
and ‘‘iridious” should not equally be shorn of their super- 
fluous penultimate syllable. A further question, concerning which 
considerable difference of opinion has prevailed, is whether 
any ous or ic terminations ought to be employed in the 
names of salts of which only one class is known—thus magnesic 
sulphate instead of magnesium sulphate, There is something to 
be said here for both systems ; and, as the diversity of practice 
does not lead to confusion, and consequently does but little 
harm (beyond in each case offending the ears of those accustomed 
to the opposite system), the question need not be regarded 
as a vital one. In the case of carbon compounds, however, 
there is a distinct advantage in affixing 7c to the names of the 
positive radicals in ethereal salts. A neglect of this precaution 
leads to ambiguity—at all events in the sfcAe7 name. Thus, 
though there is no ambiguity in the name e//yl phenjlacetaie 
when written, yet the ear cannot distinguish between it and 
ethylphenyl acetate. This ambiguity is obviated by the use of 
the termination ze—thus, ethylic phenylacetate and ethylphenylic 
acetate. In the use of the terminations ows and zc to distinguish 
different series of acids and acid-forming oxides, with the excep- 
tion of one or two isolated eases, almost perfect unanimity has 
) revailed. To sum up, the ovs and zc terminations when em- 
ployed for purposes of distinction in cases where two series of 
oxides, acids, salts, &c., are known, have been almost free from 
ambiguity, and for this reason deserve to be retained. On the 
other hand, in cases where only one series is known, those 
chemists who have employed one or other of these terminations 
have occasionally differed as to which ought to be used: the 
difficulty may be solved, as it has been done by some chemists, 
by avoiding the use of any termination in such cases. In com- 
plex cases where the above modes of naming prove inadequate, 
recourse may be had to numeral designations. These appear 
especially admissible in cases where an oxide occurs which is 
intermediate between the ows and the éc stage, and at the same 
time cannot be classed as a compound of oxides already classi- 
fied and named. Jn applying numeral designations it is most 
important to select only such as are free from hypothesis and which 
afford correct information. In this respect chemists appear not to 
have been sufficiently careful of late years. Asan example, arsen- 
tous oxide may be quoted ; this compound is frequently termed 
“arsenic trioxide,” the formula being written As,Ox,, and it is 
tacitly assumed that the molecule contains three oxygen atoms. 
There are three objections to this name :—(1) That, assuming 
the formula on which it is based to be correct, it affords no in- 
formation as to the number of avsenic atoms associated with the 
three oxygen atoms ; (2) that it involves the assumption that 
arsenious oxide does not vary in molecular weight, whatever its 
physical state ; and (3) that the formula of gaseous arsenious 
oxide is As,O;. In employing numeral designations to indic- 
ate molecular composition in cases where this is established, it 
is therefore important to express the number of atoms of each 
constituent element, as dicarbon hexachloride, C.Clg. But* in 
the case of solid and liquid bodies of whichthe molecular weight 
is unknown, or which may vary with temperature, the name 
should merely indicate the relative proportions in which the 
constituents are associated ; or, more explicitly, the name should 
indicate the proportion of the radical associated with what may 
be termed the characteristic element of the compound. No 
difficulty oceurs in the case of the chloride, or analogous com- 
pound, of the monad elements generally, these being termed 
mono-, di-, tri-, tetra-, penta-, or hexa-chloride, &c., according 
as combination is in the proportion of 1, 2, 3, 4, 5, or 6 atoms 
of chlorine to 1 atom of the characteristic element. The appli- 
cation of this system would involve the use of the names tin 
dichloride and iron trichloride (not sesqui-chloride) for starmous 
and ferric chlorides respectively, names which accurately express 
the relative proportions of metal and of chlorine in these com= 
pounds without any hypothesis as to their molecular compo- 
sition, which in the case of the former compound, at all events, 
certainly depends on temperature. It will, however, involve a 
slight departure from the existing practice when applied to 
oxides, sulphides, and other compounds of polyad elements ;! 
thus oxides of the type (R,)”’O would be termed /emi-oxides, 
since they consist of the characteristic element and oxygen in 
the proportion of ove atom of the former to /a/fan atom of the 
latter. Oxides of the type (R,)"O, would be termed sesgzé- 
oxides, since the characteristic element and oxygen are present 
in the proportion of ove of the former to ove and a half of the 
latter. Oxides of the type R,O; would be termed sesterti-oxides, 
as they contain oxygen and the characteristic element in the 
proportion of ¢wo and a half atoms of the former to ove of the 
latter. Oxides of the types RO, RO,, ROs, and RO,, would be 
termed respectively zono-, di-, tri-, and ¢etr-troxides. 
The remainder of the report treats of the various systems 
which have been proposed for the naming of acid, basic, and 
double salts. 
Report of the Commuttee appointed for the purpose of inquiring 
in to the Rate of Erosion of the Sea-Cousts of England and 
Wales, and the Influence of the Artificial Abstraction of Shinglé 
or Material in that Action (C. E. De Rance and W. Topley, 
Secretaries).—The Committee has, during the past year, received 
several Returns relating to the south and east coasts of England. 
Most of those relating to the coast south of the Thames are 
printed. The thanks of the Committee are especially due to 
Major-Gen. Sir A. Clarke, who has instructed tke officers of the 
Royal Engineers stationed around the coast to supply the Com- 
mittee with such information as they may possess or be able to 
obtain. Further returns are expected from the same depart- 
ment and from other official sources; the Committee therefore 
think it best to defer any general Report until more complete 
information is obtained. The Memorandum drawn up by Mr. 
J. B. Redman so fully sets forth the work of the Committee, 
and the importance of the inquiry referred to it, that this is now 
printed. ‘lhe Memorandum by Mr. G. Dowker, on East Kent, 
gives a sufficiently complete account of the changes of the coast 
in this district ; changes which are of especial historical import- 
ance and interest. Mr. Whitaker has drawn up a list of works 
relating to the coast-changes of England and Wales, which will 
be of great service to the Committee and to those who may 
assist in the work. ‘The Committee would again ask for the 
assistance of any who, by long residence or other means, have 
special knowledge of changes on any part of the English and 
Welsh coast. Printed forms of questions can be obtained from 
the secretaries or from any member of the Committee. 
Third Refort of the Committee, consisting of Sir Ff. Hooker, 
Dr. Giinthr, Mr. Howard Saunders, and Mr. Sclater (Secre= 
tary), appointed for the purpose of exploring Kilima-njaro and the 
adjoining mountains of Equatorial Africa,—In their last report, 
presented at Montreal, the Committee stated the arrangements 
that they had made with Mr. H. H. Johnston for undertaking 
an expedition to Kilima-njaro, and gave extracts from Mr. 
Johnston’s letters showing the progress of his expedition up to 
May, 1884. Mr. Johnston gave an account of his expedition to 
the Royal Geographical Society at their meeting on January 
26, 1885, in which he states that in consequence of the desertion 
of two natives whom he had taken out with him from Zanzibar 
as collectors, the collections were not so large as the Committee 
could have wished. Capt. Shelley prepared a report on the 
birds collected by Mr. Johnston, and Mr, F. D. Godman on 
the butterflies of his collection, after which the first sets in both 
these collections were handed over to the British Museum, as 
were also all the other zoological collections, with a request to 
the director that reports might be prepared for publication on 
such portions of them as seemed to be of sufficient interest. 
Reports on the zoological collections made by Mr. H. H. 
