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THE GENESEE FAKMEK. 2fii) 



additional nitfogen in the aliment of the plant we should increase the proportion 

 of gluten in the grain," that most people, and indeed many able chemists, have adopted 

 the belief vvitliout suflicient evidence of its correctness. We know that wheat is greatly 

 increased in qu;iiititv per acre by the application of ammonia in any available form — 

 that in fact ammonia is the one special ingredient which a manure for wheat should 

 contain. This being the case, it is not to be expected that wheat and corn, " proverbi- 

 ally characterized as yielding starchy seeds, and whose predominant peculiarity is to 

 produce carbonaceous substances, would in their most perfect state of development be 

 rich in starch rather than in gluten and other nitrogenous compounds." Mr. Lawes, 

 who has perhaps experimented more on the requirements and composition of the wheat 

 plant than any other living investigator, says on this point : 



" My experiments do not give the slightest indication of an increase of nitrogenous element of 

 wheat grain by the employment of ammoniacal manures. That the average produce of nitrogen in 

 the crop bears a certain relation to the ammonia supplied in tlie manure, is very evident ; but the 

 per centage of nitrogen in the grain can not be increased by means of it. In some experiments, the 

 quantity of ammonia supplied by the manures was from 60 to 70 lbs. per acre, and in some instances 

 more ; but the analyses give no evidence of an increased per centage of nitrogen by its supply, and 

 the highest amount obtained in the series was from an experimental plot where no ammonia was 

 supplied in the manure." 



It is very evident that we should be very careful in coming to hasty conclusions on 

 the requirements of plants, and the influence certain kinds of manure would have upon 

 them, from a simple knowledge of the chemical composition of the seeds, &c., irrespective 

 of their peculiar characteristics, and without due regard to vegetable physiology. 



It is, too, not true that the greater amount of gluten or nitrogenous substance the 

 plant contains, the more nitrogen will it be necessary to supply in the manure : for, of 

 the leguminous plants, the clover seed contains Y per cent, of nitrogen, and that of peas, 

 beans, and tares, 5 per cent., while wheat contains on an average but 2 per cent, of 

 nitrogen in dry matter ; yet it is most clearly proved that wheat requires much more 

 nitrogen for its production than either clover seed, peas, beans, or tares. The recent 

 experiments of Messrs. Way and Thompson, on the "absorptive powers of soils," throw 

 a ray of light on this interesting subject, which will probably lead to more important 

 elucidations. These gentlemen found, by a series of experiments, that the absorptive 

 power of soil was owing to the double silicate of alumina and soda which it contained 



— that when sulphate or any other soluble salt of ammonia was added to the soil, a 

 decomposition took place, the ammonia uniting with the silicic acid in the place of the 

 soda, which unites with the sulphuric acid and is washed out, while the double silicate 

 of alumina and ammonia is left in a nearly insoluble condition. We quote from Prof. 

 Way's lecture : 



" But in order that they might fully understand this part of the subject, he must explain to them 

 an idea which he had taken in reference to this double silicate of ammonia and alumina. He had 

 already stated that water did not dissolve the whole salt, but that the silicate of alumina remained 

 undissolved, while the silicate of ammonia was dissolved in small quantity. Now he had found that 

 this solution of silicate of ammonia, when carefully evaporated, dried up on the sides of the dish into 

 thin transparent scales, like very thin ghvss, and these scales were found upon examination to be 

 silica; the ammonia having evaporated with the water, and leaving the silica as a transparent varnish 

 on the dish. Was it not likely that this fact formed the true explanation of the manner in which 

 silica was deposited on the straw of wheat? He thought it might be. Chemists had always had a 

 difficulty in accounting for this deposition of silica on the straw of cereal plants by reference to the 

 soluble silieater: of pota."!! and soda; and the solubility of silica in ammonia had not been before 

 obsei-ved. \'>y the easiest and simplest process a weak solution of silicate of ammonia, in passijig 

 through the plant, might leave its silica behind ; and the probability of this explanation was increased 

 by Mr Lawks' (iljsorvation of the loss of ammonia fi'oin the soil in the growth of corn cro])3. Mr. 

 Lawes had found that for every pound of ammonia of which the nitrogen was fixed in the wheat, in 

 the shape of aluminous constituents, other four pounds were lost to the soil in the growth of the crop 



— that is to sav, that five pounds of ammonia were required to produce a quantity of wheat contain- 

 ing nitrogen equal to one j)ound of ammonia. This loss would at once be accounted for, and would 

 inevitably result, if the deposition of the silica were due to the action to which he had referred," 



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