41 



Perliaps the most important mineral element removed by farm crops 

 is phosphate of lime, or the earthy salt of bones, composed of phos- 

 j)horic acid, 55 i^arts, and lime, 45 parts. The proportion in which 

 phosphoric acid exists in 10,000 pomids of the follo^ving■ prodncts has 

 been determined by Mr. Sprengel, a celebrated German chemist, as 

 follows : 



1. Seeds not consumed on the land. 



Pounds. 



10,000 pounds of the seeds of wbeat contain of pliosplioric acid 400 



10,000 pounds of the seeds of barley contain of i)hosphoric acid "ilO 



10,000 pounds of the seeds of oats contain of phosphoric acid 70 



10,000 pounds of the seeds of beans contain of phosphoric acid 292 



10,000 pounds of the seeds of peas contain of phosphoric acid 190 



2. The straw and roots cliieflij consumed on the land, and ichose solid constituents are returned 



to the soil. 



Pouuds. 



10,000 pounds of the straw of wheat contain of phosphoric acid 170 



10,000 pounds of the straw of barley contain of phosphoric acid 1(30 



10,000 pounds of the straw of oats contain of phosphoric acid 12 



10,000 i)ounds of the straw of beans contain of phosphoric acid 226 



10,000 pounds of the straw of peas contain of phosjihoric acid 240 



10,000 pounds of the red clover contain of phosphoric acid 138 



10,000 pounds of the sainfoin contain of phosphoric acid 220 



10,000 pounds of the cabbages contain of phosphoi'ic acid 436 



10,000 pounds of the common turnips contain of jihosphoric acid 73 



10,000 pounds of the Swede turnips contain of ]jhosphoric acid 403 



10,000 pounds of the carrots contain of phosphoric acid 395 



The following is an approved estimate of the quantity of this acid 

 carried away by live stock from a farm of one hundred acres : 



Bones. 



In the bones ar.d flesli of 110 Inmljs, of 25 pounds each, at 6 weeks old 



In 40 year-old sheep of 90 pounds each 



lu 4 calves, at 5 weeks old, weighing togetlier 500 pounds 



In 4 young cows, forming 135 pounds of flesh and 35 pounds of bone each, per annum . 

 In 2 young horses, gaining the same as the last 



Lime is also dissolved by rains and carried deeper into the earth, or 

 into drains or streams, as analysis of such waters often show. As 

 might be expected, lime proves a valuable ameliorator of such lands. 



The loss of lime by cultivation is thus given by Professor J. F. John- 

 ston, as to the crojDS mentioned : 



Pounds. 



25 bushels of wheat remove from the soil, of lime 9 



50 bushels of oats remove from the soil, of lime 9 



38 bushels of barley remove from the soil, of lime 15 



2 tons of rye grass remove from the soil, of lime 33 



2 tons of red clover remove fi-om the soil, of lime 126 



25 tons of turnips remove from the soil, of lime 140 



9 tons of potatoes remove from the soil, of lime - 270 



