aJkaline menstrna. li abounds most in clayey soils and 

 Oiuy •> foams ; but evn in the smallest pai'ticlos of these 

 gt.iia ,t IS usaaiiy united to silex and oxide of iron. 



J. tine, is the f^uhstance well known in its pure state unddr 

 the name of quick !tme. U always exists in soils in combi- 

 ne ' on, and that juincipaMy with fixed air or carbonic acid,. 

 v\ iicii it is called carbonate of lime; a subsrance which 

 in the most compact fii m constitutes marble, and in it« 

 loo<>er form chaik. Lime, whim combined with sulphur 

 ric acid (oil of vitrio!), prcHuces sulphate of lime (gyp^ 

 sum), ad vviih ph-sphoric acid, phosphate of limer 

 The carbonate of lime, mixed with other substancesjj, 

 pompose? chalky soiis and marles, and it is found ie 

 soft sandy soils. ' 



Magnesia, when pure, appears as white, and in a 

 lighter powder than a;iy uf the other earths ; it is solu- 

 bl • in acid, but nit in alkaline menstrua ; it is rarely 

 f'.jund in soils ; when it does exist, it is either in com^ 

 feination with carbonic acid, or with silex and alumine: 



Animal decnmposing Matter exists in very different 

 8'itos, accorcing as the substances from which it is pro* 

 tiuoed, are different ; it contains much carbonaceous sub- 

 stance ; and may be principally resolved by heat into 

 this su!)stanee, volatile alkali, inflammable aeriform pro- 

 ducts, and carbonic acid ; it is prmcipaily found in land's 

 tJiat have been lately manured. 



Vegetable decomposing Matter is likewise very various 

 in kind, it contains usually more carbonaceous substance 

 than animal matter, and differs from it in the results of 

 its decomposition, principally in not producing volatile 

 alkali -, it forms a great proportion of all peats ; it 

 abounds in rich mould, and is found in larger orsmallOT 

 quantities in all lands. 



The saline compounds, found in soils are very levi,,, 

 and in quantities so small, that they are rarely to be dis- 

 covered. They are principally muriate of soda (com- 

 CEiOii sait)^ sul^^.hat of magnesia (Epscmi salt), and mmp^ 



