98 CHEMICAL MANUU?;S. 



In the form of nodules the phosphate is mixed with 40 per cent. 

 of foreign matter. It is sold in powder at $1.14 the 200 Ibs. Cal- 

 cined hones, reduced to powder, are worth $3.04. By reason of its 

 bulk this phosphate cannot be employed in its natural state. It is 

 used in making acid phosphate of lime. 



Sulphate of Lime. 



Sulphate of lime is nothing more than plaster, produced by the 

 combination of sulphuric acid with lime. 



It is found in great quantities in nature in a hydrated form. Its 

 composition is then 



Sulphuric acid 46.51 



Lime 32.56 



Water 20.93 



, I 100.00 



Exposed to a temperature of 120 to 130, it loses the form of 

 water and passes to the state better known under the name of plaster. 

 It is under the form of plaster that I advise its use, in preference 

 to sulphate of lime. It is then worth 38 cents the 200 Ibs. 



JUSTIFICATION BY PRACTICE, SHOWING FACTS 

 AND LAWS. 



I will borrow several proofs from the researches of 1867 which 

 merit preservation. Some relate to the conditions of the highest cul- 

 ture, others belong to middle culture. In the latter the land is rented 

 at from $2.50 to $3.50 the acre, and in the former at from $9 to $10 

 the acre. In all these conditions the use of the chemical fertilizers 

 luis been followed, by which, in the most unfavorable cases, the income 

 of the proprietor has been doubled. 



The examples cited will have the merit, besides, of showing the 

 advance the ideas we maintain have made in two years. 



I borrow the first two documents from Le Journal des Fabrieanls de 

 Sucre (The Sugar-Makers' Journal), an excellent compilation, which 

 recommends itself as much by its independence toward the criticisms 

 of coteries as by the rare merit of its publication. 



CULTURE BY MEANS OF CHEMICAL FERTILIZERS. 



1. Wheat. 



My experiments covered the space of three acres, divided into 

 three separate fields of an acre each. 



The first received in the spring of 1866 



577 Ibs. of sulphate of ammonia, or 



120 Ibs. of azote. 



177 Ibs. of real phosphate of lime in the form of acid phosphate. 



120 Ibs. of purified potash (277 Ibs. carbonate of potash). 



277 Ibs. of lime. 



Sown in beets, it produced in 1866, 53,013 Ibs. of roots. 



