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X. — On the Necessity of Compounding Miiieral Manures. By 



F. Falkner. 



I HAVE seen in the Journal of the Royal Agricultural Society several 

 reports of experiments on the application of nitrate of soda as a ma- 

 nure, which were attended with various degrees of success and 

 failure, and which have occasioned no small perplexity to the experi- 

 menters. These varying results are, however, such as might reasonably 

 be expected, upon a due consideration of the nature of manures. Farm- 

 yard manure, being derived entirely from plants, contains all the sub- 

 stances which are essential to the formation and nourishment of new 

 systems of vegetable life, and accordingly such manure seldom or never 

 disappoints the expectations of the farmer. The desired effect being 

 constantly produced, the agriculturist seldom thinks of inquiring into 

 the nature of its composition : but when this means of fertility fails, and 

 recourse must be had to some foreign substitute, it becomes indis- 

 pensable to learn of what this continually successful manure consists, in 

 order that proper substitutes should be selected. Now, plants, and by 

 consequence the manure produced from them, are found to contain most 

 or all of the following matters : — oxygen, hydrogen, carbon, nitrogen, 

 chlorine, sulphur, phosphorus, soda, potass, lime, magnesia, silica, 

 and iron, all of which, as they are constantly found in plants variously 

 combined, are unquestionably essential to their existence and nourish- 

 ment.* If we deduct from these the three first elements, oxygen, hydro- 

 gen, and carbon, which are abundantly furnished by the atmosphere to 

 the living plant, there are ten substances remaining, which are equally 

 essential, and most of which are not sufficiently supplied by the hand of 

 Nature to maintain fertility, and therefore must be artificially restored 

 to the soil from whence they were taken : these exist generally in the 

 state of salts of ammonia, lime, and magnesia, potass and soda, formed 

 by an union of those bases with phosphoric, sulphuric, muriatic, nitric, 

 and carbonic acids. As all these substances are contained in farm- 

 yard dung, which seldom or never fails, is it reasonable to expect that 

 one only of the salts above mentioned, containing no more than three 

 elements out of the thirteen enumerated, such as nitrate of soda, or 

 nitrate of potass, or muriate of soda, when used separately, can be de- 

 pended upon as a manure : in other words, that one acid and one base 

 should supply the place of five different acids and as many bases? 



It is true that each of these salts has often produced beneficial effects, 

 but this can happen only when all the other materials essential to the 

 growth of plants are already present in the soil, the effect of previous 



* " It is stated by Sir Humphry Davy that living plants are composed of certain 

 constituent principles which are derived from the air, water, and various soluble and 

 dissolved substances, mixed with the earths, and which are taken up by the roots of 

 plants and afford them nourishment and support. The results also of the long expe- 

 rience of Du Hamel led him to the conclusion that no single material can afford the food 

 of plants, and that no manure can be taken \ip by the roots of plants unless water is 

 present ; that it is neither charcoal, nor hydrogen, nor azote, nor oxygen alone, but all 

 of them together in various states and various combinations, that afford the pabulum of 

 vegetable life, and that an excess of any one sort of manure may be detrimental, and 

 cannot be useful.'" — G. Kimberlev. 



