350 



On Nitrate of Soda. 



small one-horse cart-load (17 cwts.) of nitrate would (under the 

 circumstances of the experiment above described) increase the 

 yield by 80 sacks, or eight cartloads of grain. I may be ex- 

 cused for dwelling on this disproportion of cause to effect, be- 

 cause, even in agriculture, we are now so habituated to the 

 wonders of science, that our minds become blunted, and, which 

 is material, less ready to enlist those marvels practically in our 

 own service. But if our fathers, at the opening of this century 

 only, had heard that, with one cartload of a new powder, and two 

 cartloads of salt to restrain its vigour, an effect could be produced 

 which would have cost them certainly four hundred cartloads 

 of dung, they would have been as much surprised as by learning 

 that the journey from London to Oxford, instead of seven, would 

 occupy little more than one hour. Evidently, then, we too in 

 agriculture have found a new power of our own, scarcely inferior 

 to steam in mechanics ; and though, like steam, it may cost us 

 time to gain certainty in its use, we must no more shrink from 

 testing its qualities than we would discard the service of fire 

 or of wine, because those mighty stimvilants also of body or 

 mind become fatal, if applied in excess. 



It will be worth while, therefore, to inquire into the qualities 

 of nitre, and may be interesting to trace out the first glimmer- 

 ings of our acquaintance with its influence on vegetation. So 

 early as in the Georgics, nitre is said to be used by the peasants 

 round Mantua for steeping beans before sowing that crop. But 

 an Englishman, in the days of Charles I., the accomplished 

 and gallant royalist Sir Kenelm Digby, was the first who by 

 direct experiment ascertained that barley watered with a weak 

 solution of saltpetre grew very luxuriantly. Again, under 

 Charles II., the classic writer on English country life, Evelyn,* 

 recommended that 3 lbs. of saltpetre should be dissolved in 15 gal- 

 lons of water, and then mixed with earth for a top-dressing. Yet 

 the practice did not take root, for I find no renewed mention of 

 saltpetre until 1825 and 1829, when a few trials of it were once 

 more made, and with success. But the price was too high for 

 its profitable application as a manure. Fortunately, just as 

 science became ready to prove the agricultural efficiency of 

 nitre, widening comm.erce opened to us a fresh source of supply 

 by bringing a new kind from the plains of Peru — cuhic saltpetre, 

 which cannot be used for the old object, the fabrication of gun- 

 powder, but is even richer, as will be shown presently, than 

 common saltpetre, for the peaceful purposes of the farmer. 



The old nitre is quoted now at 29Z. per ton ; the new, or cubic, 

 nitre, at 16/., little more than one-half, with a prospect, too, as I 



* For this reference, as ■w'ell as the former^ I am indebted to Mr. Ciithbert 

 Johnson's work on Fertilizers, p. 346. , 



