94 AgricuUurc. [Chap. VIU, 



the Phy.nology of Vegetables. These inquiries liave 

 led to new and important conclusions, respecting 

 the food of plants, and the best means of promoting 

 vegetation. On- this subject much valuable infor- 

 mation has been communicated to the public by 

 Hales, Hill, Walker, and Darwin, of Great Britain; 

 by du Hamel, des Fontaines, Broussonet, and 

 1 lassenfratz, of France ; by Ingenhousz, van Hum- 

 boldt, and Jacquin, of Germany; and by Bonnet 

 and Sennebier, of Geneva. 



The eighteenth century is remarkable for the 

 numerous improvements which, in the course of 

 it, have been introduced into agriculture, through 

 the medium of Chemistry. Indeed, the modern ap- 

 plication of chemical doctrines to the cultivation of 

 the earth, may be considered as forming a grand 

 era in the history of science. In this application 

 of chemical philosophy many^ persons have distin- 

 guished themselves, and rendered important service 

 to agriculture. Amoni^ these the earl of Dhndonald 

 is entitled to particular notice^. He had the ho- 

 nour of publishing one of the first formal treatises 

 on this subject. He has been followed by many 

 others, \\ ho have pursued the inquiry much further, 

 and with great success. 



The nature and advantages of particular Soils 

 have been, more or less, the objects of inquiry in 

 all ages. But inquiries of this "kind, in the 

 course of the eighteenth century, have been more 

 numerous, enlightened and useful, than ever be- 

 fore. A number of pliilosophers, during thi.^ 



^ Sec hii; work on ih-j Comexio7i of Agriculture vjith Chemistrij. 



