on 



On the Inorganic Constituents of Plants, 



colour of the blades and the superior height of the plants increased, 

 and remained very marked until the wheat came into ear. 



2. Phosphate of Ammonia and Silicate of Potash. The same 

 quantity of Phosphate of Ammonia was used in this, as in the pre- 

 ceding experiment. The plants received in addition a quantity of 

 pure silicate of Potash, corresponding to a hundred weight and a 

 half per acre. The silicate employed was very pure, having been 

 made by slowly fusing together white quartz sand, previously well 

 boiled in nitro-muriatic acid and thoroughly washed, with pure car- 

 bonate of Potash. It was white, perfectly transparent, and entirely 

 soluble in water. The silicate was applied to the plants in solution, 

 a weak solution being poured between the rows, taking care not to 

 wet the blades. The produce was 



The proportion of corn to the whole crop was therefore as 

 1137 to 10000. One thousand seeds weighed 584 grains. The 

 standard measure full weighed 4070 grains, hence the bushel would 

 weigh 58^ lbs. The remarks just made with respect to No. 1, 

 Phosphate of Ammonia alone, may be equally applied to this 

 square, which like No. 1 might until the plants came into ear be 

 easily distinguished at a distance from the four following squares by 

 the superior height and darker green colour of the blades. The 

 quantity of corn produced both in Nos. 1 and 2 was less than had 

 been expected from the appearance of the plants and the size and 

 quantity of the ears formed ; it is probable that a considerable 

 portion of the corn was carried away from both these squares, but 

 more particularly from No. 2, by the birds ; it being more exposed 

 than the other squares to their depredations. 



3. Sulphate of Soda. The substance taken in this experiment 

 was not a pure sulphate of Soda, but the impure salt, called Salt 



