16 AMERICAN AGRICULTURE. 



entirely free from lime, or not to contain more than five pei 

 cent., and 



8. Calcareous soils, in which the lime exceeding 20 pei 

 cent, becomes the distinguishing constituent. These are 

 also calcareous clays, calcareous loams, or calcareous sands, 

 according to the proportion of clay and sand which are 

 present in them. 



The determination of the lime also, when it exceeds five 

 per cent., is attended with no difficulty. 



To 1QO grs. of the dry soil diffused through half a pint of 

 cold water, add half a wine glass-full of muriatic acid (the 

 spirit of salt of the shops), stir it occasionally during the day, 

 and let it stand over night to settle. Pour off the cleai 

 liquor in the morning and fill up the vessel with water, to 

 wash away the excess of acid. When the water is again 

 clear, pour it off, dry the soil and weigh it the loss wih 

 amount generally to about one per cent, more than the quan- 

 tity of lime present. The result will be sufficiently near, 

 however, for the, purposes of classification. If the loss 

 exceed five grs. from 100 of the dry soil, it may be classed 

 among the marls, if more than 20 grs. among the calcareous 

 soils. 



Lastly, vegetable matter is sometimes the characteristic 

 of a soil, which gives rise to a further division of 



9. Vegetable molds, which are of various kinds, from 

 the garden mold, which contains from five to ten per cent., 

 to the peaty soil, in which the organic matter may amount 

 to 60 or 70. These soils also are clayey, loamy, or sandy, 

 according to the predominant character of the earthy ad- 

 mixtures. 



The method of determining the amount of vegetable 

 matter for the purposes of classification, is to dry the soil well 

 in an oven, and weigh it ; then to heat it to dull redness over 

 a lamp or a bright fire till the combustible matter is burned 

 away. The loss on again weighing is the quantity of organic 

 matter." 



The foregoing are only such general divisions, as possess 

 properties sufficiently common to each, to require a treatment 

 nearly similar. Besides their principal component parts, 

 every soil must contain in greater or less quantities, all the 

 elements which enter into the composition of vegetables. 

 They may have certain substances which are not necessary 

 to vegetable life, and some one or all of such as are, may be 

 contained in excess ; yet to sustain a healthy prolific vegeta- 



