Use of Saltpetre and Nitrate of Soda as Manures. 279 



equal portions of land dressed witli saltpetre. You may he aware 

 that this nitre is rather more than 30 per cent, cheaper than the 

 saltpetre.* I was absent from home at the hay-harvest, but my 

 bailiff assures me that there was not a perceptible difference 

 between the produce of the saltpetre and the nitrate of soda, 

 applied in such proportions. 



I have not myself used saltpetre on arable ground, but I have 

 seen it applied in this neighbourhood as a top-dressing for wheat 

 and barley. It gives great richness to the appearance of each 

 when they are growing ; but I. doubt the effect upon the yiekl of 

 the corn : of this, however, I have no positive knowledge. 



About 2 cwt. of saltpetre per acre is an ample dressing. 



I have the honour to be. Sir, 



Your obedient servant, 



Dacre. 



The Hog, near Wehinjn, Hertfordshire^ 

 January lAth, 1840. 



* Nitrate of soda is found in layers on the surface of the earth in the 

 western part of South America, and is brought on mules to the coast, where 

 it undergoes a process of refining, so that it never contains more than 5 per 

 cent, of alloy in the original packages in the Docks of London, while saltpetre, 

 or nitrate of potash, has come over from the East Indies, and Turkey with 

 from 30 to 50 percent, of alloy ; it is always bought, however, by the dealers 

 at a price calculating the refraction as alloy at 5 per cent., although the 

 quality of the article may differ widely in its proportion of the real salt, and, 

 in order to obtain the full extent of beneficial effects of this saline manure 

 on the land, a genuine and pure article is indispensable. With regard to 

 the price, nitrate of soda in the Docks is now sold by Mr. William Mitchell, 

 of the Commercial Sale Rooms, Mincing-lane, London, at 196'. 6c?. per cwt., 

 duty paid; and saltpetre, or nitrate of potash, at 255'. per cwt., duty 

 paid ; calculating the refraction at 5 per cent. Saltpetre is now cheaper 

 than it was last year, and the nitrate of soda 10 per cent, dearer ; but, having 

 been found on trial on the same soils to be equal in its effect with saltpetre, 

 towards March both will probably advance in price, when the great con- 

 sumption is likely to take place ; and considering the prices of grain, and 

 the generally known results of the manure of saltpetre for the last twenty 

 years, it is very probable that, in spite of the disparity of price, both articles 

 will be largely used for further experiments on the different soils. I have 

 sold during the last year nearly 2000 tons of nitrate of soda, and the present 

 stock in the Docks in London is under 1000 tons: of saltpetre, we have 4000 

 or 5000 tons in the Docks, but a demand of 1500 to 2000 tons for agricul- 

 tural purposes would raise the price too high for its use. — [Note by H. F. 

 TiARKS, Esq., Consul-General to the Grand Duke of Oldenburg, and Mer- 

 chant in the City of London. — Communicated by his Grace the Duke of 

 Richmond.] 



