194 



PROCEEDINGS OF THE CHEMICAL DEPARTMENT. 



method. This process, which is described in the more recent 

 works on chemical analysis, is founded on the principle of sub- 

 jecting the soil to a regulated current of water, by means of 

 which the finely-divided portion of the soil is levigated away 

 from the coarser part. The whole is first divided into gravel, 

 by sifting it through a sieve with eight holes to the inch, and 

 the soil is then levigated in such a manner as to obtain coarse 

 sand, fine sand, clay, and organic matter. Schultze separates 

 the coarse sand into two parts, by means of a sieve with 

 forty holes to the inch, and calls that which does not pass 

 through, gravelly sand; but I have not thought it advisable 

 to draw this distinction. The calculation of the mechanical 

 analysis is made in the dry soil, after deduction of the organic 

 matters. It is to be noticed that it includes the gravel ; and this, 

 and the absence of water, are the reasons why the quantity of 

 organic matter in the chemical and mechanical analyses do not 

 correspond. It would require some detail to explain the mode 

 of calculation, but any one acquainted with the analysis of 

 soils can easily see how it is executed. The soil is, in every 

 case, a fair sample of the upper ten inches, and the subsoil of 

 the ten inches immediately below ; and they were taken by 

 cutting a slice from the side of a trench of the required depth. 



I shall prefix to each analysis a short account of the external 

 characters of each sample. 



SOIL EROM THE FARM OF DIRLETON, ON WHICH MR HOPE'S 

 EXPERIMENTS WERE MADE. 



This soil, which lies close to the sea, was light and sandy, and, 

 although clayed at the rate of 200 carts per acre, still had much 

 the appearance of a dirty sea sand. The soil itself had a some- 

 what dark colour, due to organic matter, and contained a number 

 of white specks, which were found to be carbonate of lime. 

 The subsoil retained more of the characters of sea sand, but 

 clay and lime had penetrated into it, though not to so great an 

 extent, the particles of carbonate of lime being much less 

 numerous. There was no gravel in either the soil or subsoil. 



Soluble in Acetic Acid. 



Peroxide of Iron, 



Alumina, 



Lime, 



Magnesia, 



Potash, 



Soda, 



Sulphuric Acid, 



Chlorine, . 



Phosphoric Acid, 



Total Soluble in Acetic Acid, 



1-572 



1-521 



