62 CHEMICAL MANURES. 



dantly. I have laid down the principle in this lecture that the 

 chemical fertilizers, whose exclusive use I first studied, can be ad- 

 vantageously associated with barnyard manure, and I have showed 

 you the manner of making this new application. To complete these 

 first indications, it remains for me to take up the questions in detail, 

 and show you the most convenient formulas for this especial case. . 



This finishing of our first studies is the more necessary, since the 

 production of manure is, in a certain measure, a necessity we cannot 

 avoid, as it has to do with the working of the land. 



This new subject will make the object of our next lecture. 



LECTUEE SIXTH. 



HENTLEMEN: In all clearings of a certain extent the work of 

 \JT animals is indispensable ; culture by the hand of man is not pos- 

 sible when we operate on a scale of importance with regard to certain 

 products of large relations, such as the vine, the hop, tobacco, etc. 

 I repeat, then, when we enter the domain of agricultural tillage, 

 properly speaking, the intervention of animals being a necessity 

 born of the force of circumstances, manure is produced, and we are 

 absolutely compelled to take notice of it and learn to regulate the 

 employment of it. 



I take up the question, then, from the point where I left it in our last 

 .meeting, and to complete the general ideas I gave you on the use of 

 manure and chemical fertilizers mixed, there remains for me but to 

 point out to you the practical rules to be followed in such cases. 



Our first example is from a succession of five years, the same 

 practiced at Bechelbronn, comprehending, as you know, the follow- 

 ing rotation : 



1st year, Irish potatoes. 



2d year, wheat. 



3d year, clover. , 



4th year, wheat. 



5th year, oats. 



At the opening of the fallow the earth received from 35,555 to 

 44,444 pounds of manure. Now, in 44,444 pounds of manure the 

 four terms of the complete fertilizer are represented by 



Azote 183 Ibs/ 



Potash 156 " 



Phosphoric acid \ 97 " 



Lime 355 " 



You will remark that at least one-third of the azote of the manure 

 is lost to the soil, on account of the previous decomposition the ma- 

 nure must undergo before it can show its eifects. With so small a 

 quantity of manure the returns are doubtful. To change this state 

 of things, and put the land under culture, we must at least double 

 the quantity of agents of fertility by means of the chemical fer- 



