206 DURATION OP SALTS OP LIME. 



n ate, and therefore more liable to be wasted by rain-water surcharg- 

 ing the soil. This result can neither be affirmed nor denied, from 

 any positive knowledge of such facts, or of the chemical changes 

 necessary for them. We do not know which of the vegetable acids, 

 nor how many of them, at once or successively, may combine with 

 the lime ; and therefore cannot know what other salts of lime will 

 be produced. The humate of lime, which, it may be presumed, 

 will be the most abundant of such>produets, is difficult of solution 

 by water. If oxalate of lime should be formed (as is probable, 

 where sorrel was before an abundant growth), that is an insoluble 

 salt, and therefore safe from this manner of loss. The acetate of 

 lime, another probable result, is easily -soluble in water ; and per- 

 haps other vegetable and soluble salts may be formed in soils, 

 though more rarely and in less quantity than the humate and oxa- 

 late of lime. Besides, there are other soluble salts of lime named 

 by Prof. Johnston, and quoted above. But, however little may 

 be known by chemists or others of the kinds and quantities of these 

 salts into which carbonate of lime is gradually changed, by access of 

 different vegetable or other acids, it appears, from the general and 

 abiding effects on fertilization and production, that all these differ- 

 ent salts of lime continue to perform, and as fully, all the enduring 

 functions of carbonate of lime. For when a soil, after having been 

 made slightly calcareous, has in time become neutral (and of course 

 its carbonate of lime has been all converted to other salts of lime), 

 the soil thereby loses none of its so acquired fertility or value, 

 through any succeeding known time. This could not be the case 

 if the lime in its new condition was liable to certain and rapid, and 

 finally complete waste, by dissolving and escaping waters. In a 

 former chapter (pp. 96, 97,) I maintained that the serviceable and 

 acting lime in soil (for of course any quantity in excess is not so 

 considered) becomes chemically combined with the organic, or ali- 

 mentary manuring principles present, and all these with other earthy 

 parts of the soil. Judging from the abiding effects, and in regard 

 to neutral soils, it may be safely inferred that such combinations 

 occur not only with the carbonate, but with nearly all the later 

 produced salts of lime, resulting from the carbonate. And if so, 

 such combination with other insoluble and permanent matters of the 

 soil, would render as fixed and permanent even the salts most solu- 

 ble and liable to waste when alone. Of this, I will state an ex- 

 ample that will be familiar to every one. Sulphate of iron (copperas) 

 is easily soluble in water ; and, if alone, would be soon removed 

 completely by the dissolving water passing away. The red juico 

 of fresh nut-galls would be nearly as easily taken up, and washed 

 off by water. But these two substances, if meeting together, would 

 chemically combine, making ordinary black ink ; which cannot be 

 washed away by water from any substance to which it is attached } 



