SUCH WASTE OF LIME DENIED. 



Hence the water that flows from the drains upon such lands is 

 always impregnated with lime, and sometimes to so great a degree 

 as to form calcareous deposits in the interior of the drains them- 

 selves. . . The loss of lime from these causes cannot be 

 estimated, and must vary with the exposure to rains, and slope of 

 surface, &c. But the cause is universal jind continually operating, 

 and would alone therefore render necessary, after the lapse of years, 

 the applications of new doses of lime." (p. 399.) 



Answer. These several chemical powers, &c., are fully admitted. 

 But their action, under usual and proper conditions of limed or 

 marled land, must be very limited, even when any such agency of 

 waste can be produced. Caustic lime, as stated above, may be 

 sparingly dissolved in pure water. But lime, applied as manure, 

 does not long remain caustic, and, after ceasing to be so, is no 

 longer the least exposed to this particular source of loss ; and marl, 

 or carbonated lime, is not at all so exposed. As carbonate of lime, 

 however, and while so remaining, another means of solution is 

 operating, in the carbonic acid of the air. But the quantity of 

 this acid is so small, and its tendency to be absorbed by water so 

 great, that a very light rain, or merely the beginning of a long or 

 heavy rain, must bring all the then floating carbonic acid to the 

 soil. This fluid would immediately sink into the pores of the earth, 

 with its dissolved carbonate of lime, if any ; and there be preserved, 

 either mechanically or chemically (by further and speedy combina- 

 tion with other matters of the soil), so as to be very little if at all 

 subject to removal in superfluous water before being saved and put 

 to use as manure in later-formed and more fixed chemical combina- 

 tions. This particular source of waste cannot apply at all but to 

 lime in the form of carbonate. And, according to my previously 

 expressed views, that form is soon changed (with moderate and 

 proper dressings) to other salts of lime, or combinations with the 

 organic parts and the other earths of the soil. In such case, the 

 last considered outlet for waste is also closed ; but, possibly, and 

 as Prof. Johnston supposes certainly, others are opened, and will 

 operate, as thus : 



3. " During the decay of vegetable matter, and the decomposi- 

 tion of mineral compounds, which take place in the soil where lime 

 is present, new combinations are formed in variable quantities, 

 which are more soluble than the carbonate, and which therefore 

 hasten and facilitate this washing out of the lime by the action of 

 rains. Thus chloride of calcium, nitrate of lime, and gypsum, are 

 all produced of which the two former are eminently soluble in 

 water while organic acids [as humic, acetic, &c. &c.J also result 

 from the decay of the organic matter, with some of which the lime 

 forms readily soluble compounds (salts), easily removed by water/' 

 (p. 399.) 



