COMPOST FERTILIZERS. 247 



The theory adopted is, that there must be organic matter in 

 a moist condition, with ready access of air, in order to carry out 

 those changes which have been alluded to. But I do not speak 

 authoratively upon this point. The gentlemen whom I address, 

 have a much more extended experience, perhaps, to guide them. 



After what has been said regarding the employment . of 

 specific fertilizers, it is probable, gentlemen, that you will have 

 anticipated the recommendation that I have to make, and that 

 is, always to compost or compound elements of nutrition designed 

 for plants, until a system is established, which will enable us to 

 use single substances understandingly. Chemistry in its appli- 

 cation to agriculture, has certainly made advances, inasmuch as 

 it is now capable of demonstrating the correctness of two impor- 

 tant propositions : first, that each field has its own peculiar 

 wants ; second, that each plant has its own peculiar appetite. 

 It has further established its claims to respect and confidence, 

 by showing that meteorological influences being favorable, we 

 can supply requisite food in the proper quantity and condition, 

 to secure the largest crops, with a great degree of certainty. 



The system of Professor Ville already referred to, embraces 

 this idea. He proposes the use of what he denominates a per- 

 fect manure, that is, one made up of nitrogen, phosphoric acid, 

 lime and potassa. This, when made up and applied in proper 

 quantities, he shows is capable immediately of changing a barren 

 siliceous soil into one of perfect fertility. 



I am willing to accept these results in general as in accord- 

 ance with my own experimental observations during the past 

 three years, or rather I yield assent to the correctness of the 

 principle of producing and applying perfect manures. It is 

 noticeable that magnesia is omitted as an element in his 

 manure, par excellence. As we have before stated, there is 

 present in most soils, or there is constantly being formed by 

 decomposition, the minor substances like iron, manganese, 

 chlorine, <fcc, sufficient for the wants of vegetable organisms, 

 but magnesia cannot be classed with them, as a glance at the 

 composition of some important grains will show. 



The ash of wheat affords 12 per cent., or 12 ounces 

 in one hundred ; the straw more than 3 per cent. ; barley, 

 7 ; oats, 10 ; rye, 10 ; corn, 8 ; turnips, 2. These quantities 



