On the Inorganic Constituents of Plants, 



experiments however shewed, that the proportion of inorganic to 

 organic matter, was increased in a greater proportion by salts of 

 Ammonia than by salts of the fixed Alkalies. The following are a 

 few examples of their effects. 



Perfectly similar plants of broad leaved summer Spinach were 

 manured, some with Sulphate of Ammonia, and others with Nitrate 

 of Potash ; the salts being applied in tolerably large quantity, as a 

 top dressing. Both manures produced a remarkable effect, in- 

 creasing the size of the leaves very greatly, and causing the plants 

 to grow with the utmost vigour. On examination they were found 

 to consist of 



By the last column it appears, that a considerably larger quantity 

 of inorganic matter was taken up, T>y the plants manured with sul- 

 phate of Ammonia, than by those treated with Nitrate of Potash ; 

 the former also were the most succulent, but in size and appear- 

 ance when growing, there was no perceptible difference. 



A similar experiment was made with Shallots. The colour of 

 the plants was much darkened, and their size was increased, but 

 not to the same extent as with the Spinach. The Shallots con- 

 tained 



A third experiment on Tobacco also gave a similar result ; in 

 this case Phosphate of Ammonia was compared with Nitrate of 

 Potash. The plants were examined after flowering, and were much 

 older than those described in a previous experiment, (p. 39.) The 

 composition of the leaves and stalks was 



