Minute Ingredients of Soil. 437 



An acre contains 4840 square yards, or 43,560 square feet : 1 foot in 

 depth throughout would be 43,560 cubic feet of soil Assuming an 

 average specific gravity to be 160 lbs. per cubic foot, 43,560 cubic feet 

 would weigh 6,969,600 lbs., which for convenience may be called 

 7,000,000 lbs. 



No. 2, Mersey Court, Liverpool^ 

 9th July, 1842. 



Note. — May we not ask chemists whether an intimate mixture of all the ingredients 

 above enumerated in the analysis would form a soil similar to the one analysed? Would 

 the sulphuric acid remain uucumbiued with the peroxide or protoxide of iron, or the 

 chalk, potash, and soda? or would they not form neutral salts? Would the chlorine 

 remain uiicombined? It may be very interesting to know all the elements contained 

 in any soil; but unless we know how they are combined, and how their combination 

 affects fertility, we are not much more advanced. In comparing the two soils here 

 analysed — one of which is fertile and the other barren — we are surprised to find that the 

 last contains 75,100 lbs. of humus and the first only 47,000 lbs. per acre. Wliat are the 

 elements which may be the cause of barrenness in the one and fertility in the other, if 

 we leave out the different size and quality of the silicious sand and alumina, carbonate 

 of lime and magnesia? The first contains four-fifths oi' ffie silicious sand, and 3 per 

 cent, of alumina, with 4 per cent, of carbonate of lime and magnesia. Tlie other Cv?n- 

 tains 95 per cent, o^ coarse silicious sand, with little more than ^ per cent, of alumina, 

 and no carbonate of lime. These circumstances, which the roughest analysis would 

 have discovered, are sufficient to account for the difference between fertility and bar- 

 renness. The other ingredient throws no light on the subject as far as the farmer is 

 concerned. — W. L. Rham. 



XII. — Eximiments with Guano. By George Pryme. 



To the Secretary. 



Sir, — I now detail to you my two experiments with guano manure. I 

 made them on a highland and a fen farm, both in my own occupation, in 

 the parish of Wistow, 7 miles N.E. of Huntingdon. 



The surface of the former is very undulating, and its soil, though 

 of the same nature, varies somewhat in tenacity. I have had a portion 

 of it analysed by Mr. R. Phillips, of the Geological Museum, Craig's 

 Court. He informs me that " 56 ozs. of the sod contained 1 J oz. of 

 silicious stones. These were picked out previous to analysis, not being 

 considered as constituting a part of the real soil One hundred parts of 

 the soil thus separated from the stones gave very nearly as under : — 



Silica or silicious earth . . , 68 '9 



Alumina or clay-earth . . . 9" 7 



Oxide of iron 8*1 



Carbonate of lime or chalk , . 2*8 



Vegetable matter 4*0 



Water 6*5 



100-0 



