70

that were picked out, and find the proportionbelonging to each pound of the residuary earth;call this the stony supplement, and denote it byS. Thus if the stones weigh 1 lb. “12 oz. theremainder, or mere earth, must weigh 5,661b.and if to 5,661b. there belong 12 ozs. of stone,to lib. must belong 2,12014 ozs. or 2 ozs.57,66 grains r= 1017,66 grs. This then is thestony supplement of each succeeding pound=zS.

3 0- Of the earth thus freed from stony mat-ter, take lib.— S. (that is the above case lib.—2oz. 57 two-thirds grs.) heat it nearly toredness in a flat vessel, often stirring it for halfan hour, and weigh it again when cold. Itsloss of weight will indicate the quantity of watercontained in lib. of the soil. Note this loss,and call it the watery supplement—W. Supposeit in this case 100 grains.

4°* Take another pound of the above massfreed from stones, deducting the stony andwatery supplements; that is lib.—S—W, orin the above case lib.—2 ozs. 57 two-thirds grs.for stone, and—100 grains for water; conse-quently lib.—2 ozs. 157 two-thirds grs. reduce