580 Agriculture. 



a respectable German clergyman/ Since that 

 time this substance has been used with much suc- 

 cess, not only in Germany, but also in several other 

 parts of Europe, as well as in America; but the 

 manner in which it produces its fertilizing effects, 

 notwithstanding the numerous and diligent inqui- 

 ries which have been made on the subject, is still 

 far from being satisfactorily unfolded. 



The efficacy o{ Carbon, or common Charcoal, in 

 promoting vegetation, was first ascertained, a few 

 years ago, by M. Hassenfratz, a celebrated 

 French chemist. He found that this substance is 

 an essential ingredient in the food of all vegeta- 

 bles, and that soils are, in general, fertile in pro- 

 portion to the quantity of it which they contain. 

 The properties and effects of carbon as a manure 

 have been since diligently and successfully ex- 

 amined by various other writers and experimenters 

 on the subject. 



The general use of Marie, Lime, Chalk, and 

 various combinations of calcareous matter, as 

 means of increasing the fertility of the soil, is 

 chiefly of modern date. And even with respect 

 to these, and such other manures as were in a de- 

 gree known and employed in ancient times, the 

 mode of their operation, the best methods of apply- 

 ing them, and the various circumstances which 

 should attend the application, have been incom- 

 parably better understood, within a few years past, 

 than in any former period. The most scientific 

 «nd satisfactory modern writers on manures, in ge- 

 neral, are Dundonald, Middleton, Darwin, 

 and Tennant, of Great-Britain; Kir wan, of 

 Ireland; Parmentier, of France; Ruckert and 

 Von Uslar, of Germany; and Eller, Walle- 

 rius and Gyllenborg, of Sweden. 



X Transattlons of the Royal Irish Academy y vol. V. p. 1 96. 



