362 



On Nitrate of Soda. 



perhaps less, as was the case the year before last on Lord 

 Leicester's own farm at Holkham.* On land out of condition it 

 might even give more — it gave me last year upon ground pur- 

 posely impoverished, eight bushels.f But if it be true, as it 

 appears to be, that nitre yields six bushels, and guano only three 

 bushels per cwt., though each contains nitrogen to the same 

 amount, how is this unexpected conclusion to be accounted for ? 

 This question is also practically important, for two reasons. To 

 reduce the price of guano is a matter of pressing interest, for 

 last year 245,066 tons of guano were imported into this country, 

 and sold to our farmers for more than two millions sterling, of 

 which sum nearly one million is drawn from them by foreign mono- 

 poly, though that official monopoly does not unfortunately secure 

 us in the quality of the supply, which appears to be adulterated 

 at the fountain-head with plaster of Paris, sent out thither from 

 Liverpool ;J yet we know no probable source of cheap ammonia 

 as a substitute for that contained in guano. Again, the top- 

 dressing of young corn is year by year more widely practised, 

 and it greatly behoves us to ascertain which of the two sub- 

 stances we should employ for this special purpose. If guano be 

 inferior for it to cubic nitre, one reason may be that the ammonia it 

 contains is a fugitive^ while nitrate is ajixed salt. Consequently 

 in dry weather guano may produce no effect whatever on the 

 actual crop, as I have myself experienced ; and, being wasted by 

 the wind, no effect afterwards. I may mention too, as it is in 

 fact an experiment upon a large scale, that last spring, when I 

 was preparing to apply the nitrate to my own frosted barley, I 

 counselled a neighbour to try the same dressing. Though an 

 excellent farmer, he adopted only half the advice, preferring 

 guano as the cheaper manure. He could not perceive afterwards 

 that the guano had produced the slightest effect on his barley, 

 while the nitrate had so much benefited mine on the same soil 

 and in the same season. Mr. Lawes, too, assures me that 

 throughout his many experiments he has lost one-half of the 

 ammonia contained in his guano, the corresponding nitrogen not 

 re-appearing in the yield of grain and of straw. Nitrate, on the 

 contrary, would lie safe on the surface beneath a scorching sun, 

 and will then as we know act upon the following crop. On the 

 other hand, in a rainy season. Nitrate will very likely, especially 

 if applied in a full dose at once, be washed down too rapidly 



* Journal, vol. xiii., p. 201. f Journal, vol. xii., p. 203. 



X "Four vessels recently sailed hence for guano stations, ballasted with gypsum, 

 or plaster of Paris. This substance is intended for admixture with guano, and will 

 enable parties to deliver from the vessel a nice-looking and light-coloured article." 

 — Liverpool Paper. Professor Johnston's ' Elements of Agricultural Chemistry,' 

 6th ed., p. 234. 



