134 



THE FARMERS' REGISTER. 



P. S. — Since writing the above, the No. of 

 the Cabinet for February has reached me, and I 

 find that your correspondent, Mr. Lewis, ol'Potis- 

 ville, has enibrticed the opinion that the presence 

 of magnesia in lime is not injurious for agricultural 

 purposes, nay, that it is " diametrically opposed 

 to it ;"' and to this decision he has been brought, 

 not by a " two-penny expermient made in a gar- 

 den-pot, or the cornert)!' a field," hut by its ex- 

 tended use over hundreds of thousands ol acres 

 through a long period ofyears, in opposition to the 

 " would-be oracles of the day," or the theory thai 

 has been " babbled," on the subject. Now, by 

 8uch men as your correspondents, iVlessrs. Kinser 

 and Lewis, 1 presume we shall be sure that the 

 subject will be properly treated, and the truth 

 elucidated, but 1 would meekly ask why do these 

 gentlemen use such strong language to express 

 themselves, if they are not in some way interest- 

 ed in the matter? Surely it does not require such 

 terms of contempt and reproach to silence the 

 workers in a garden-pot or the corner of a field, 

 or these very small oracles or babblers who pre- 

 sume to arise in their path 7 S. 



Luzerne county, February 23, 1842. 



REMARKS ON THE OPPOSITE OPIMONS OF 

 WAGNESIAN LIJIE. 



In the Farmers' Cabinet there has been recent- 

 ly revived, and is warmly contested, the old con- 

 troversy as to the alleged deleterious action of 

 magnesia in lime. Two of the articles are insert- 

 ed above, which set Ibrth the opposing views. 

 This still doubtful question is one of tlie many 

 subjects of opprobrium to agricultural science — 

 or rather of chemical science pretended to be ap- 

 plied to agriculture. Chemical writers have been 

 content to repeat, and merely theoretical farmers to 

 believe, the opinion of Tenant, announced half 

 a century ago ; which opinion, however interest- 

 ing and important to agriculture, and however 

 true might be the particular experiment on which 

 it rested, vvras certainly not established generally 

 and fully. Other and varied experiments ought to 

 have been made, both by chemists, and by practi- 

 cal farmers who had it in their power to try and 

 compare the effects of lime fi^om both pure and 

 magnesian limestones. But while the various print- 

 ed articles of argument, or loose discussion, would 

 have filled a volume, there has not been carried 

 through a single series of judiciously planned and 

 accurately conducted experiments, which, if per- 

 formed, would have decided all doubts, and re- 

 moved every obstacle to this all-important branch 

 of improvement in a very large agricultural region. 



The fact that magnesian lime in large quanti- 

 ties is injurious or even destructive to vegetation 

 and to productiveness of soil, however certain, is 



by no means a proof that the application of mag- 

 nesia (either in its calcined and pure state, or 

 when carbonated and mild,) is hurtful. There 

 are other manures (indeed most others) highly 

 beneficial in proper quantities, which are injurious 

 in excessive quantities. Pure lime itself is ad- 

 duced by the witnesses on one side to show that 

 it may be applied in any quantity without damage 

 to vegetation, and that benefit is Ibund by increas- 

 ing the dose to 500 or even 1000 bushels, in the 

 caustic slate, at one application. Yet, without 

 undertaking to deny these particular facts, (as we 

 know nothing of the precise conditions of the 

 trials,) it is certain that our liming farmers in 

 lower Virginia find 150 bushels dangerous, and 

 100 bushels or even less often unsafe. Yet no 

 farmers in our region have made more profitable 

 improvements, except the marlers, than those who 

 have used lime. The kind most generally used 

 by them, and from which all their facts o( injury 

 by excess have been derived, is oyster-shell lime, 

 which is pure lime, containing no magnesia or 

 other foreign matter. 



Of shell marl, or merely calcareous marl, the 

 principal and almost sole fertilizing ingredient is 

 mild lime or carbonate of lime ; and when we first 

 commenced its use, we had no idea that any 

 quantity of it could injure land by its excess. 

 Yet a few j'ears' experience showed great injury 

 from applications containing not more than 200 

 and sometimes less than 150 bushels of the pro- 

 portion of this mild lime. The richer the marl of 

 course the greater the injury from a heavy dress- 

 ing. Yet what farmer of common sense would 

 therefore denounce the use of marl as injurious, 

 or would prefer the poor to the rich, because 500 

 bushels of the poor produced great and continued 

 increased product, while 5C0 of the rich would 

 produce disease and great injury to the grain 

 crops, (or many years? 



Theorists have extended the sound objections to 

 caustic magnesia being applied too heavily as ma- 

 nure in newly burnt lime, to the existence of car- 

 bonate of magnesia naturally in soils, or in ma- 

 nures ; and have inferred that, even in this mild 

 or natural form, it was the cause of sterility. We 

 have no practical knowledge of magnesian soils ; 

 but cannot believe that a substance so simi- 

 lar to lime in its chemical qualities can be so dif- 

 ferent in its operation as manure. Soils may in- 

 deed be barren from an excess of magnesia in 

 their natural composition (if there be any such) 

 as others certainly are because of excess of lime ; 

 and others by excess of the siliceous and others of 

 the clayey ingredient. But any quantity of mag- 

 nesia that could possibly be applied as manure, 



