1864.] CHEMISTRY OF MANURES. 99 



those of light and heat, began to be better understoocl, as well in 

 their general relations, as in their special influence on plants. 



The introduction of more accurate chemical methods permitted, 

 meanwhile, a closer investigation than had before been possible, of 

 the tissues and products of plants, and of the various transforma- 

 tions which those products undergo during the several stages of 

 vegetal development. 



The sound physico-chemical principles thus established had the 

 happiest influence on physiological investigations. The organs 

 of plants and of animals were studied in a clearer light than 

 before; and their respiratory, assimilative, and excretory processes, 

 together with the relations established by those processes between 

 the three great kingdoms of nature, were gradually made out. 



Among the many illustrious men who assisted in working out 

 thes3 great results, Lavoisier probably deserves the highest place ; 

 not, perhaps as the largest contributor of new truths to the accu- 

 mulating store, — though his contributions of this kind were many 

 and brilliant, — but because his vivid imagination, and the eminent 

 generalizing powers with which he was endowed, enabled him to 

 co-ordinate all the scattered researches of his time, and to display 

 innumerable isolated facts in their true subserviency to general 

 laws; so as (among other things) largely to extend our knowledge 

 of the cosmic equilibrium on which sound husbandry can alone be 

 based. Everything, indeed, that Lavoisier did bore the impress 

 of his master-mind. He it was who first applied the Balance to 

 the study of the phenomena of Life. He it was who first showed . 

 that while plants evolve oxygen, animals, on the contrary, consume 

 it ; carbon being oxidized or burned in their bodies as oil is burned 

 in a lamp. His lofty tone of thought, and eloquent language, 

 powerfully impressed his contemporaries; and chiefly to his influ- 

 ence and example the admirable researches of his age owe their 

 high scope and scrupulous precision. Science never endured a 

 severer loss than when Lavoisier met his untimely fate. But his 

 great spirit lived after him ; and researches bearing upon the 

 noble themes he had loved to treat were carried on with, if pos- 

 sible, increased activity after his death. The scientific records of 

 Europe were soon crowded with fresh masses of undigested dis- 

 covery ; and in a few years such another mind as his was wanted, 

 to grapple with the growing mass of detail, and once more to create 

 order out of the scientific chaos. 



