150 LESSONS ON CHEmSTRY. 



degree, to its value (184), by retaining matters which, as 

 that manure is usually managed, are lost to the farmer. 



232. Inorganic matters contained in peat. — In an exami- 

 nation, lately made of this manm-e, as it is usually prepared 

 by skilful farmers in Scotland, it was found that every hun- 

 dred pounds of peat charcoal, placed on a field, would convey 

 to it the following ingredients. The proportion of ashes will, 

 of course, vary, according to the extent to which the air is 

 allowed to penetrate to the heap, in burning the peat, 

 and their composition will also be difierent, in various 

 samples. 



Charcoal, 6412 



Sulphates of Potash, Soda, and Magnesia, 6 "5 7 



Alumina, 2-99 



Oxide of Iron, 4-61 



Sulphate of Lime (gypsum), , 10*49 



Carbonate of do 8*54 



Phosphate of do 0'90 



Siliceous matter, 10*88 



99*10 



The above mixture affords the very materials which every 

 plant that is grown must procure, to form its leaves, its 

 stalk, and its seeds. 



233. The amount of phosphate of lime in charred peat is, 

 however, not sufiicient to induce the farmer to rely upon it as 

 his only manure, for a number of years; and it will be 

 advisable for him to apply with it some of the fertilizers 

 above described.* 



* I was lately favoured by J. J, Burnett, Esq. Glenarm, with a state- 

 ment of the results of some experiments made by him at Gadgirth, in 

 Ayrshire, with mixtures of charcoal, kelp, and other manures, which 

 are exceedingly interesting. 



Experiments with various manures — Crop, Swede turnips. 



Applied per Scotch acre. Weight per Scotch acre. 



No. 1. 20 tons of farm manm-e, 1 cwt. African) go tons 10 cwt 



guano, 1 cwt. charcoal (wood), 3 



No. 2. 20 tons farm manure, 2 CAvt. Peruvian) o-. ^^ns 



guano, 1 cAvt. wood charcoal, 3 



No. 3. 20 tons farm manure, 1 cwt. African guano, \ go ^ . ^ ^^^^ 

 8 bushels ground kelp, 2 cwt. salt, S 



No. 4. 20 tons farm manure, 4 cwt. concentrated^ qi ^ 



' >- £)1 tons, 



manure, ) 



