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THE GENESEE FARMER. 281 ' ^' 



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MAPES' IMPROVED SUPERPHOSPHATE OF LIME. 



Once more we are under the necessity of referring' to this article. It is not that we have 

 any pecuniary interest in this matter, or that, as Mr. Mapes' asserts, we are sold to puff 

 the superphosphate manufactured by a rival house. We are personally unacquainted with 

 Mr. Mapes, Mr. De Burg, Mr. Patxerson, and all other manufacturers of superphos- 

 phate. Their commercial interests sink into insignificance when compared with the 

 chemico-agricultural principles involved in this question — principles which, to our view, 

 lie at the very foundation of a judicious rotation of crops, and of a rational system of 

 agriculture. From the introduction of superphosphate of lime we anticipate great 

 improvements in American agriculture. We have as high an ppinion of the value of 

 superphosphate as a fertilizer as has Mr. Mapes ; and we have as earnestly advocated 

 its extensive use. What we object to in Mr. Mapes is his extravagant praise of his own 

 catch-penny "improvement" in his Workinq Farmer — his recommending it as the best 

 and cheapest manure for all crops, and his absurdly ridiculous assei-tion that his 

 " improved superphosphate of lime" can not be manufactured in England for one 

 hundred dollars per ton, and that, to his certain knowledge, if it could be, it would 

 immediately take precedence of all other manures. 



Of the articles in which we have stated our reasons for the views we entertain on this 

 subject Mr. Mapes has taken no notice. Opinions without reasons are of little conse- 

 quence, but as we have previously given the reasons, we may be pardoned for again 

 stating, as briefly as possible, our opinions on this subject. 



As reg£irds the value of superphosphate of lime, we know that for turnips and ruta 

 bagas it is the best manure in the world, but to obtain its full effect it must be drilled 

 with the seed. In consequence of this, the improvement of Mr. Mapes, which consists 

 in the addition of Peruvian guano and sulphate of ammonia to the mixture, is a decided 

 injury, as these substances are injurious to the germination of the seed when drilled 

 with it. For clover, mangel i^'urzel, cabbages, carrots, celery, lettuce, and tomatoes, 

 superphosphate is a good manure, though were both the same price we should prefer 

 Peruvian guano. For wheat, barley, oats, potatoes, and, we believe, though we have no 

 experiments of our own to sustain the opinion, that for corn and timothy superphosphate 

 of lime, in ninety-nine cases out of one hundred, will be found of no essential value. 

 These opinions are directly opposed to the teachings of that large class of agricultural 

 chemists to which Mr. Mapes belongs, who think that the composition of the a.shes of 

 plants afford a true index of the relative proportion in which the elements of plants 

 should exist in the manure applied to them. This is a very plausible deduction, but, 

 unfortunately, like many other beautiful theories, experiments and the experience of 

 practical men prove it to be unsound. For instance : the ash of wheat and of the 

 cereal grains generally contains 50 per cent, phosphoric acid, while the ash of turnips 

 and ruta bagas contains only 10 per cent. Yet an extensive series of carefully conducted 

 experiments, as well as the universal experience and practice of English farmers, prove 

 that phosphoric acid is of no direct benefit to wheat and to the cereals generally, while 

 for turnips and ruta bagas it is the most essential element of a manure. Thousands of 

 tons of superphosphate are annually used in England as a manure for turnips, while 

 from personal observation we know that superphosphate is never used as a manure for 

 wheat, and is not even recommended by the manufacturer as a manure for any of 

 the cereals. 



Again, this imj^roved superphosphate of lime, according to Mr. Mapes' certain knowl- 

 edge, can not be manufactured in England for less than |100 per ton. This we have 

 previously shown to be a very silly mistake, inasmuch as phosphate of lime, sulphuric 

 acid, guano, and sulphate of ammonia, the ingredients which Mr. Mapes says he puts 



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