ANALYSIS OF SOILS. 81 



in. 



On the Analyfis of Soils, as connected wiih their Improvement. 

 £y Humphrey Davy, Efq. F. R. S. ProfeJf>r ofChemiftry 

 to the Board of Agriculture and to the Royal Injlitution. 



I. Utility of Inveftigation relating to the Analyfis of Soils. 



A HE methods of improving lands are immediately connected 

 with the knowledge of the chemical nature of foils, and ex- 

 periments on their competition appear capable of many ufeful 

 applications. 



The importance of this fubject has been already felt by fome Analyfis of 

 very able cultivators of fcience ; many ufeful facts and obfer- to by ' Mr> 

 vations with regard to it have been furniihed by Mr. Y ang; Young, Lord 

 it has been examined by Lord Dundonald, in his Te on ^k™L™ A 



the connexion of Chemiftry with Agriculture, and by Mr. 

 Kirwan in his excellent eflfay on Manures : but the enquiry is 

 (till far from being exhaufted, and new methods of elucidating 

 it are almoft continually offered, in confequence of the rapid 

 progrels of chemical difcovery. 



In the following pages I mall have the honour of laying 

 before the Board, an account of thofe methods of analyfing 

 foils which appear mod prectfe and fimple, and mod likely to 

 to be ufeful to the practical farmer ; they are founded partly 

 upon the labours of the gentlemen, whofe names have been 

 juft mentioned, and partly apon fome later improvements. 



II. Of the Subjiances found in Soils. 



The fubftances which are found in foils, are certain mixtures Soils contain 



or combinations of fome of the primitive earths, animal and ^ r d th v s ' ™JJ£ 



vegetable matter in a decompofing ftate, certain faline com- remains, faKne 



pounds, and the oxide of iron. Thefe bodies always retain *<™P°*"**, and 

 * J oxide of iron, 



water, and exift in very different proportions in different lands ; 



and the end of analytical experiments is the detection of their 



quantities and mode of union. 



The earths found in common foils are principally filex or 

 the earth of flints, alumine or the pure matter of clay, lime, 

 or calcareous earth, and magnefia. 



Silex, or the earth of flints, when perfectly pure, appears in Silex, ; 



the form of a white powder, which is incombuftible, infufible, 



Vol. XII.— October, 18Q5. G intoluble 



