AGRICULTURF. WITH CHEMISTRY. . i^^^' 



deprived of the water of clirystallization, and broiv^ht to 



an equal degree of dryness, the quantity of calcareous 

 matter and magnesia in eacli may be ascertained by Berg- 

 MAisi'sor Kirwan's tables of the proportion of acid, al- 

 kali, earth, and water contained in different neutral salts. 

 To those who are not provided with such tables, it may 

 sufEcc to say, that 



uicid Cakai\ Matter Water 

 loopartsof gypsum contain 48 34 iS 



Acid Magnesia Water 



ioo parts of Epsom salt contain 33 19 48 



As both clay and sand, in different proportions con- 

 stituting either a clayey or sandy soil, are distinguishable 

 by the sight and touch, there is no occasion for giving 

 any chemical test, to prove their presence. The pro- 

 ])ortion of the coarser parts of siliceous matter or sand, 

 in soils or mould, may be ascertained by washing. 



The presence of vegetable or-carbonaceous matter in sur- 

 face mould, when in any considerable proportion, is ap- 

 parent, either from its Idack colour, or from the vcge- 



u 2 table 



