ANALYSIS OF SOILS. 47 



and qualities are different; that they are cold or 

 warm, wet or dry, porous or compact, barren or 

 productive, in proportion as one or the other may 

 predominate in the soil ; and that, to fit them for dis- 

 charging the various functions to which they are 

 destined, each must contribute its share, and all be 

 minutely divided and intimately mixed. In this great 

 work nature has performed her part ; but, as is usual 

 with her, she has wisely and benevolently left some- 

 thing for man to do. 



This necessary interposition of human industry 

 should obviously begin by ascertaining the nature 

 of the soil. But neither the touch nor the eye, how- 

 ever practised or acute, can in all cases determine 

 this. Clay, when wet, is cold and tenacious ; a de- 

 scription that belongs also to magnesian earths : 

 sand and gravel are hard and granular ; but so also 

 are some of the modifications of lime : vegetable 

 mould is black and friable, but not exclusively so : 

 for schistous and carbonaceous earths have the same 

 properties. 



It is here, then, that chymistry offers herself to ob- 

 viate difficulties and remove doubts ; but neither the 

 apparatus nor processes of this science are within 

 the reach of all who are interested in the inquiry, 

 and we accordingly subjoin a method less compre- 

 hensive, but more simple, and sufficiently exact for 

 agricultural purposes, and which calls only for two 

 vases, a pair of scales, clean water, and a little sul- 

 phuric acid. 



" 1st. Take a small quantity of earth from differ- 

 ent parts of the field, the soil of which you wish to 

 ascertain ; mix them well together, and weigh them ; 

 put them in an oven heated for baking bread, and, 

 after they are dried, weigh them again ; the differ- 

 ence will show the absorbent power of the earth, or 

 the quantity of water which it contained. When 

 the loss of weight in 400 grains amounts to 50, this 

 power is great, and indicates the presence of much 



