268 



Lime and Magnesia. 



Vol. VII. 



The action of lime and magnesia, as re- 

 gards the promotion of decay, is precisely 

 similar; the only difference being, that mag- 

 nesia is more caustic than lime, — takes 

 longer to carbonate, and is less soluble in 

 water. Both lime and magnesia, when car- 

 bonated, possess in a degree, alkaline pro- 

 perties, and act in the same manner, but 

 with less intensity, as they do in the caustic 

 state. 



The magnesia being longer in carbon- 

 ating, perhaps more alkaline when carbon- 

 ated, and less liable to be dissolved in water, 

 and washed from the soil by rain, accounts 

 for the experience of a neighbour, who told 

 me he could see where a certain lime, 

 whose stone contained from 30 to 40 per 

 cent, of carbonate of magnesia, was put on 

 20 years ago, while the effect of another, 

 containing no magnesia, spread five years 

 since, had entirely disappeared. 



That magnesian lime spread upon grass 

 in considerable quantity, will, owing to its 

 highly caustic nature, kill the grass in con- 

 tact with it, argues nothing but its superior 

 alkaline properties above mentioned. The 

 same quantity or more, if incorporated com- 

 pletely with the soil, or spread in successive 

 small portions at different times, would show 

 no such effect, but would produce a soil, other 

 things being the same, susceptible of the 

 greatest degree of fertility. A sufficient 

 quantity of ashes spread upon grass, will act 

 in the same way as too much at a time of 

 magnesian lime ; yet who says that ashes 

 are not most valuable ] 



If then the virtues of pure lime, lie in its 

 alkaline properties — and magnesia is more 

 alkaline than lime, — is it not consistent with 

 the plainest common sense to declare, that 

 less of the latter will answer, in place of the 

 former'? 



Again, when we consider the general 

 economy of nature, it is no far drawn infer- 

 ence to conclude, that whatever ingredients 

 we invariably find in a fertile soil, are es- 

 sential to its constitution; and if absent, 

 must be supplied. 



Liebig has given us the analysis of a con- 

 siderable number of soils, amongst which, 

 there is not one noted as being very fertile, 

 but it contains a considerable portion of lime 

 and magnesia. I will extract from some 

 which bear particularly upon our question. 

 The parts are stated in hundredths and deci- 

 mals of hundredths, which in most I have 

 reduced to bushels per acre. One soil con- 

 tained lime 0.038, magnesia 0.147 or 25 

 bushels to the acre, potash and soda 0.09, 

 and it is remarked: "This soil was much 

 improved by manuring with lime and ashesj" 

 evidently to supply the lime and potash. An- 



other soil contained lime 1.028, or 175 bush- 

 els to the acre ; magnesia only a trace. In 

 the subsoil of the same, was lime 0.296, 

 magnesia .095, or about 17 bushels to the 

 acre. The remarks are ; " This soil pro- 

 duces luxuriant crops of lucerne and sain- 

 foin, as well as all other plants whose roots 

 penetrate deeply into the ground. The rea- 

 son is apparent. The subsoil contains mag- 

 nesia, which is wanting in the surface soil." 



Another, a "very fertile soil," to which 

 no manure had ever been applied, gave lime 

 5.88, or 1000 bushels to the acre, magnesia 

 0.84, or 147 bushels to the acre. Another 

 very fertile field gave lime 1.2, or 209 bush- 

 els per acre, magnesia 1.04, or 175 bushels 

 per acre. Another soil, " remarkable for its 

 fertility, having never been manured or al- 

 lowed to lie fallow, and yet has produced for 

 the last 100 years, the most beautiful crops, 

 contains lime 0.927, or 170 bushels to the 

 acre, magnesia 1.16, or 200 bushels to the 

 acre." Surely in 160 years, the poisonous 

 qualities of 200 bushels per acre, of caustic 

 magnesia, had time to show themselves! 

 Yes, and they have shown themselves, in 

 preventing the soil from being impaired in 

 its fertility, by the accumulation of unde- 

 composed and putrifying vegetable excre- 

 ments. Another " very fertile'' surface soil, 

 gave carbonate of lime 3.77, or 665 bushels 

 to the acre, carbonate of magnesia 4.066, or 

 700 bushels to the acre, while its subsoil 

 gave 3000 bushels of carbonate of lime and 

 2000 carbonate of magnesia to the acre. 

 Lastly, the " surface soil of alluvial land in 

 Ohio, remarkable for its great fertility," 

 gave lime 0.619, or 100 bushels to the acre, 

 magnesia 1.024, or 175 bushels to the acre. 

 What a pity, the enterprising emigrant to 

 the inexhaustible fertility of the West, can 

 not escape from magnesia ! ! 



I will just suggest to friend Van Leer, 

 that if he will have his soils analysed, he 

 will not only find carbonate of lime, as 

 hinted by the L. C. Farmer, but magnesia 

 also, in all his good soils, and some other 

 cause independent of those, to account for 

 the inferior fertility of some limed parts of 

 his land. And if he had just said what kind 

 of rocks were in his friend's field, it might 

 have helped one to guess what it was that 

 had " run out," since he thinks it was not 

 the lime. 



In conclusion, let every farmer whose land 

 is not calcareous, give it lime or limestone; 

 if not magnesian, give it magnesian lime- 

 stone, lime, or epsom salts; give it plaster 

 to fix the ammonia of the atmosphere, and 

 to retain that of the soil and its contents; 

 give it potash in the form of ashes, to make 

 the wheat stand stiff", and glaze the corn- 



