BRITISH ASSOCIATION FOR ADVANCEMENT OF SCIENCE. 673 
the whole area of the vast field of chemical, mineralogieal, and agricul' 
tural research which the objects of this section embrace, which would 
justify me in the ambitious hope that I could command your attention 
as I am aware that my predecessors in this chair have done on some 
former occasions, while placing before you a summary of the progress 
made since our last meeting in these branches of knowledge, and 
delineating the leading features of their present, and the prospects of 
their future state. In this I should be sure to fail, and therefore I shall 
not attempt it, though I cannot help giving expression to my surprise 
and admiration of the astonishing developments which they have under- 
gone, I will not say since the time when my own acquaintance with 
chemistry commenced by hanging in rapt enthusiasm over Macquer’s 
‘Dictionary’ (which seemed to me in those early days a work of little 
short of superhuman intelligence) 3 nor since the epoch when a Davy 
electrified the world by the decomposition of the alkalies ; nor that when 
a Faraday commenced his magnificent career of discovery ; or when a 
Berzelius first showed what might be done in giving precision to analy- 
sis — but since organic chemistry has assumed, by the experiments and 
reasonings of Dumas, Liebig, Hoffmann, and its other distinguished 
cultivators, that highly abstract and intellectual form under which it 
now presents itself, and which, by the links of the platina bases, and 
compounds such as those described by Gibbs and Genth under the name 
of the ammonio-cobaltic bases, and by those which are every day coming 
into view by the mutual interweaving, if I may use such an expression, 
of the organic and inorganic systems of composition in bases such as 
those of the metallic ethyls and those of boron and silicon — seems to 
place these conceptions in much the same sort of relation to the ordinary 
atomic theory as put forth by Dalton and Higgins, and the elementary 
notions of oxide, acid, and base of Lavoisier, that the transcendental 
analysis holds to common algebra.” 
After a word of declamation against the system of 
notation into which chemists had fallen in expressing atomic 
formulae, as not being in accordance with algebra, he adverted 
to the 
Grouping of the Elementary Bodies. 
“ The time is perhaps not so very far distant when, from a knowledge 
of the family to which a chemical element belongs, and its order in that 
family, we may be able to predict with confidence the system of groups 
into which it is capable of entering, and the part it will play in the com- 
bination. A great step in this direction seems to me to have been lately 
made by Professor Cooke, of the Harvard University, of the United 
States (in a memoir which forms part of the fifth volume of the ‘ Memoirs 
of the American Academy of Arts and Sciences’), to extend and carry 
out the classification of chemical elements into families of the kind I 
allude to, in a system of grouping, in which the first idea, or rather the 
first germ of the idea, may be traced to a remark made by JM. Dumas, 
in one of his reports to this Association, and which is founded on the 
principle of arranging them in a series, in each of which the atomic 
weight of the elements it comprises are found among the terms of an 
arithmetical progression, the common difference of which in the several 
series are 3, 4, 5, 6, 8, and 9 times the atomic weight of hydrogen re- 
spectively. So arranged they form six groups, which are fairly entitled 
to be considered natural families, each group having common properties 
