100 THE CANADIAN NATURALIST. [April, 



Early in the present century England, in her turn, produced a 

 master-mind, — that of the illustrious Sir Humphrey Davy, — vast in 

 scope and luminous in conception, as any, the greatest, of foregone 

 times. Davy was well fitted to wear the fallen mantle of Lavoisier, 

 and to continue his great work. It is accordingly to Davy's 

 genius we owe that memorable treatise — truly described by 

 Liebig as '^ immortal " — the " Elements of Agricultural Chem- 

 istry." 



In that imperishable work all the scattered results of foregone 

 research in this branch of science were collected and reduced to a 

 system, which was extended and enriched by the author's own 

 capital researches ; whereof, perhaps, the most signal (in this 

 depai tment of science) were his analytical investigations of soils 

 (types of all that has since been done in that way) ; his capital 

 determinations of the composition and transformations of vegetal 

 products; and his admirable experiments on the nutrition of plants, 

 as well by leaf as by root. 



To the powerful impulse and just direction impressed by Lavoi- 

 sier in France, and Da>y in E.igl md, in subsequent investigations 

 of like kind, may be ascribed in a great measure their vigorous 

 and successf il prosecution by philosophers contemporary with our- 

 selves. Of these an encyclopaedic list cannot,of course, be given here ; 

 and among so many equally illustrious names, it would be difficult 

 to single out a few, as types to represent the rest. Suffice it to 

 say, that to the exertions of these able men we owe a large propor- 

 tion of the experimental data, on which, as on a firm foundation, 

 the edifice of modern agricultural science, physical, chemical, and 

 physiologic jI, has, so to speak, been, stone by stone, built up. 

 Honor and gratitude to those who have patiently hewn out those 

 stones from ihe quarry of undiscovered truth ! 



B t as the true value of the quarried stones is only made 

 appircnt by their judicious collocation in tiie edifice according to 

 the plan of the architect, so also do experimental data, separately 

 accumulated by the toil of many, only appear in their true value 

 and significance when comprehensively embraced, co-ordinated, 

 and, as it were, fused into a harmonious whole, by the fiery genius 

 of one master-mind. Such a mind was Lavoisier's in the last 

 century ; such a service was rendered by Davy to our fathers ; 

 and such, to ourselves, are the mind and the service of Justus 

 Liebi- 





