376 



Nitrate of Soda as a Manure. 



Soon after, one weaker solution had begun to act. It was onl}r 

 the weakest dose of all which produced no effect. The three 

 strongest too had killed the blades alone of the grass, not the roots, 

 which in about a fortnight sent up a new crop of deeply dis- 

 coloured herbage, resembling that produced on their side by the 

 nitrate of soda. The quantities of acid applied are given in the 

 following table : — 



September 22. 



Manure employed on Area 

 of 5 square feet. 



Nitrate of soda . 



Ditto 



Nitric acid of commerce 



Ditto 



Ditto 



Ditto . . . . . 

 Ditto . . . . . 

 Ditto 



Quantity 

 in 



Drachms.'^ 



6 

 3 



8 

 6 

 4 

 2 

 1 



Water 



in 

 Pints. 



Effect on Grass, 

 perfection being 

 taken at 10. 



10 

 9 

 8 



At this time, November 15th, the effect of the waterings is still 

 very conspicuous, the grass so treated being not merely darker 

 but thicker, and three times longer on the best lots than on the 

 adjoining turf. 



Having thus discovered that nitric acid did act, and having 

 ascertained the safe dose, I made two further trials, which in- 

 cluded the alkalies separately, soda and potash, and also included 

 ammonia to serve as a further test. In both trials the nitric acid 

 acted decidedly. The alkalies, neither of them, produced even a 

 trace of effect on the colour or on the growth of the grass : — 



Manure employed on Area 

 of 5 square feet. 



Nitrate of soda 

 Nitric acid . 

 Ammoniaf . 

 Sodaf . . 



Nitrate of soda 

 Ditto . . 

 Nitric acid . 

 Ammonia 

 Potashf . 



October 3. 



Quantity 

 in 



Drachms. 



6 

 4 

 If 

 1| 



October 4. 

 6 

 3 

 2 



n 



3 



Water 



in 

 Pints. 



Effect on Grass, 

 perfection being 

 taken at 10. 



10 



10 

 5 

 7 

 5 

 0 



* The drachms express, of course, the weight of the dry salts and the measure 

 of the liquid acid, 

 t The carbonates of ammonia, soda, and potash. 



