236 
BRITISH ASSOCIATION. 
Trenham Keeks, T. IT. Rowney, Dr. Schunck, Wentworth L. Scott, Maxwell Simpson, 
R. Angus Smith, H. C. Sorby,* J. C. Spiller, C. Tomlinson, Prof. Yoelcker, Dr. J. E. De 
Yry, F. Wrightson. 
Thursday. 
The President (Prof. W. A. Miller) said:—“Amongst the problems which have, for 
some time past, been engaging the minds of philosophical chemists, few are of greater 
interest than those connected with the idea of the atomicity of the elements. It is well 
known that chemists now distinguish between the atomic weight and the equivalent of 
an element; also that, owing to the labours of many distinguished men, amongst whom 
the names of Williamson, Kekule, Odling, Cannizzaro, and Wurtz are the most promi¬ 
nent, a classification of the elements into families has been made; and that this classifi¬ 
cation rests upon what is known as the atomicity of the elements. One group of the 
elements, like potassium and chlorine, is regarded as monatomic , or usually equivalent in 
functions to one atom of hydrogen; a second, like oxygen and sulphur, is diatomic , or 
equivalent in functions to two atoms of hydrogen; a third group, like nitrogen, phos¬ 
phorus, and arsenic, is trialomic , or equivalent for the most part to three atoms of hydro¬ 
gen ; while a fourth group, like carbon and silicon, is tetratomic , or equivalent in func¬ 
tions to four atoms of hydrogen, and so on. It would lead us too much into detail were 
I to attempt to show how this idea of the atomicity of the elements has been applied, 
and is still in process of application, to the study of the formation of compounds in ge¬ 
neral, how it endeavours to explain the existence of a limit to their number, and how it 
even teaches us to anticipate their possible varieties. Among the subjects connected 
with its development is its bearing upon isomerism , or the remarkable fact of the exist¬ 
ence in many cases of two or more bodies of different properties, but yet composed of 
the same elements, combined in identically the same proportions. Upon this subject, 
which, at our last Meeting, was characterized by Dr. Odling as the chemical problem of 
the day, a suggestive theoretical paper was published, about twelve months ago, by Dr. 
Crum Brown; whilst, in the same direction, Cahours, Kekule, Beilstein, Fittig, and seve¬ 
ral other chemists, have published valuable experimental researches. Inquiries of this 
kind are now acquiring special importance from the numerous cases of the formation of 
such isomeric bodies by the method of synthesis and substitution, which are daily multi¬ 
plying. Closely connected with the same subject are the investigations into the consti¬ 
tution of the more complex organic acids, which have been prosecuted so actively during 
the last five or six years, and which, in the hands of Kolbe, Frankland, Perkin and 
Duppa, Kekule, Wurtz, and their pupils, have made such rapid progress. During the 
past year Frankland and Duppa have especially signalized themselves by their researches 
upon the lactic and the acrylic series. Two years ago, Frankland, commencing with 
oxalic ether, and acting upon it with zinc ethyl, obtained from it leucic ether by substi¬ 
tuting ethyl for a portion of the oxygen contained in the oxalic ether; and afterwards, 
conjointly with his friend Duppa, he has generalized this reaction. Still more recently, 
these chemists have traced the connection between the lactic and the acrylic or oleic 
series, by reactions in which the abstraction of the elements of an atom of water from 
the basylous portion of a member of the lactic group converts it into the corresponding 
member of the acrylic series. In these and kindred investigations, the necessity for the 
introduction of fixed principles of nomenclature for regulating the construction of names 
for the recently-discovered compounds has been sensibly felt; and indeed the changes in 
notation rendered necessary by the alteration in the values assigned to the atomic 
weights of many of the chemical elements have rendered a general revision of the system 
of chemical nomenclature a matter of pressing importance. Probably few subjects could 
more usefully occupy a portion of the time of this Section during the ensuing week than a 
thoughtful consideration of the changes which it may be expedient to introduce. The 
meeting of chemists from various parts of Europe with many from distant parts of our 
own country affords an excellent opportunity for discussing a subject of this kind, where 
any conclusions, to be practically effective, must secure the concurrence of a majority of 
the active cultivators of the science. Passing allusion only can now be made to some of 
the processes of mineral and metallurgic chemistry, such as the improvements in the 
details of the process for preparing magnesium, the comparative facility with which the 
recently-discovered metals thallium, rubidium, and caesium, and their compounds may be 
obtained, and the application by Redtenbacher of his observation of the sparing solu¬ 
bility of their alums to the extraction of the new alkalies from the lithium residues of 
