ss 



and earth, by 

 carbonate of 

 potajh. 



.A'uTijne if 

 taken up. 



Carbonate of 

 lime if in p'entv, 

 jnay betftimated 

 by ihe quantity 

 ef carbonic acid. 



ANALYSIS OF SOIL?. 



Into the fluid freed from oxide of iron, a folution of neu T 

 tralized carbonate of potato mufi be poured till all effervescence 

 ceates in it, and till its tafte and fmell indicate a confiderable 

 excefs of alkaline fait. 



The precipitate that falls down is carbonate of lime; it 

 mutt be collected on the filter, and dried at a heat below that 

 of rednefs. 



The remaining fluid mud be boiled for a quarter of an hour, 

 when the magnefia, if any exifi, will be precipitated from 

 it, combined with carbonic acid, and its quantity is to be 

 afcertained in the fame manner as that of the carbonate of 

 lime. 



If any minute proportion of alnmine fhould, from peculiar 

 circumftances, be diflblved by the acid, it will be found in 

 the precipitate with the carbonate of lime, and it may be 

 feparated from it by boiling for a few minutes with foap lye, 

 (ufficient to cover the Mid matter. This fubftance diflblves 

 alumine, without acling upon carbonate of lime. 



Should the finely divided foil be fuffidently calcareous to 

 effervefce very firongiy with acids, a very fimple method may 

 be adopted for afcertaining the quantity of carbonate of lime, 

 and one fuffkjently accurate in all common cafes. 



Carbonate of lime, in all its dales, contains a determinate* 

 proportion of carbonic acid, i. e. about 45 per cent, fo that 

 when the quantity of this eiaftic fluid, given out by any foil 

 during the folution of its calcareous matter in an acid is known, 

 either in weight or meafure, the quantity of carbonate of lime 

 may be eafjly difcovered. 



When the procefs b) diminution of weight is employed, two 

 parts of the acid and one part of the matter of the foil mufi: 

 be weighed in two feparate bottles, and very flowlv mixed 

 together till the effervelcence ceafes ; the difference between 

 their weight before and after the experiment, denotes the 

 quantity of carbonic acid loll ; for every four grains and a half 

 of which, ten grains of carbonate of lime mult be eftimated. 



The beft method of collecting the carbonic acid, (o as to 

 difcover its volume, is by the pneumatic apparatus, the con- 

 flruclion and application of which is deicribed at the end of 

 this paper. The eftimation is, for every ounce meafure o£ 

 carbonic acid, two grains of carbonate of lime. 



X. Mode 



