lviii report — 1865. 



been attended to ; but the Association has not yet succeeded in obtaining a 

 complete digest of the facts and theories connected with the appearance of 

 crystals in nature — in the fissures of rocks ; in the smaller cavities of rocks ; 

 in the solid substance or liquid contents of other crystals. Such an inquiry, 

 however, it did earnestly demand, and some steps have been taken by our 

 own chemists, mineralogists, and geologists. But more abundant information 

 on this class of subjects is still needed, even after the admirable contributions 

 and recent discoveries of Bischof, Delesse, and Daubre'e *. 



Within our Association-period both the nomenclature of chemistry and the 

 conception of the atomic theory have received not indeed a change, but such 

 an addition to its ordinary expression as the more general language and 

 larger meaning of Algebra have conferred on common arithmetical values. 

 The theory of compound radicals, as these views of Liebig, Dumas, and Hof- 

 mann may be justly termed, embraces the consideration of groups of elements 

 united in pairs by the ordinary law, these groups being for the purpose in 

 hand treated as single elements of combination. The nomenclature which 

 attempts in ordinary words to express these relations grows very unma- 

 nageable even in languages more easily capable of polysyllabic combinations 

 than ours ; but symbols of composition — the true language of chemistry — 

 are no more embarrassed in the expression of these new ideas than are the 

 mathematical symbols which deal with operations of much greater com- 

 plexity on quantities more various and more variable f. The study of these 

 compound radicals conies in aid of experimental research into those numerous 

 and complex substances which appear as the result of chemical transforma- 

 tions in organic bodies. Thus in some instances the very substances have 

 been recomposed by art which the vital processes are every moment pro- 

 ducing in nature ; in others the steps of the process are clearly traced ; in all 

 the changes become better understood through which so great a variety of 

 substances and structures are yielded by one circulating fluid ; and the result 

 is almost a new branch of animal and vegetable physiology, not less import- 

 ant for the health of mankind than essential to the progress of scientific 

 agriculture. 



The greater our progress in the study of the economy of nature, the more 

 she unveils herself as one vast whole ; one comprehensive plan ; one universal 

 rule, in a yet unexhausted series of individual peculiarities. Such is the 

 aspect of this moving, working, living system of force and law : such it has 

 ever been, if we rightly interpret the history of our own portion of this rich 

 inheritance of mind, the history of that Earth from which we spring, with 

 which so many of our thoughts are coordinated, and to which all but our 

 thoughts and hopes will again return. 



How should we prize this history ! and exult in the thought that in our 

 own days, within our own memories, the very foundations of the Series of 

 Strata, deposited in the beginning of time, have been explored by our living 

 friends, our Murchison and Sedgwick, while the higher and more complicated 

 parts of the structure have been minutely examined by our Lyell, Forbes, 

 and Prestwich + ! How instructive the history of that long series of inhabi- 



* Bischof, Chemical Geology (published by the Cavendish Society, 1856). 



Delesse, Etudes sur le Metamorphisme, 1858, and other works. 



Daubree, Sur la Relation des Sources Thermales des Plombieres, avec les Filons Metal- 

 liferes et la Formation des Zeolithes, 1858, and other works. 



+ On the Nomenclature of Organic Compounds, by Dr. Daubeny. Reports of British 

 Association, 1851. 



I The investigations of Murchison and Sedgwick in the Cambrian and Silurian Strnta 

 began in 1831 ; the views of Sir C. Lyell on Tertiary periods were made known in 1829. 



