ON MANURES. 



III9 



Comparing the food-requirements of the various kinds of fruits 

 with those of the vegetables, we find that the range* of con- 

 stituents is not so great with the matured fruit as it is with the 

 succulent and immature vegetable. Potash is especially abundant 

 in all kinds of fruit, and there is a fairly, uniform range in the 

 quantity of phosphoric acid. Lime is extracted from the soil 

 by Grapes and Tomatoes to a much greater extent than by the 

 other fruits enumerated. Apples are large consumers of the 

 ingredient soda, while Grapes require scarcely any soda at all. 



Investigations have shown that an average crop of Apples 

 from a tree ten to fifteen years old remove from the soil, in 

 round numbers, i2lb. of nitrogen, 61b. of phosphoric acid, and 

 321b. of potash ; and that the leaves of a tree large enough to 

 produce the Apples would contain iolb. of nitrogen, 31b. of 

 phosphoric acid, and iolb. of potash; or a total of 2 2lb. 

 nitrogen, 91b. phosphoric acid, and 421b. potash. 



These analyses throw some light on the great sustaining power 

 of Grapes as food for sick persons. In one ton weight of 

 Grapes will be found 3631b. of dry substance, 2olb. of mineral 

 matter (ash), 3^1b. of nitrogen, iolb. of potash, 31b. of phos- 

 phoric acid, and 2051b. of sugar. 



SELECTED CONSTITUENTS IN THE ASH OF DIFFERENT 

 KINDS OF FLOWERS, IN 1001b. OF EACH. 



Here again is shown an enormous range in the chemical 

 constituents of the different flowers of the garden, the ingredient 

 potash varying from 7 per cent, to 30 per cent. ; phosphoric 

 acid from 7 per cent, to 42 per cent. ; lime from 10 per cent, 

 to 26 per cent. ; and soda from 2 per cent, to 36 per cent. 

 The large quantity of soda in Cacti is most remarkable, and 

 clearly points to the special requirements of this class of plants. 



