40 Absorption of Phosphate of Lime; and 
The 314 lbs. of mineral matter in the bulbs, and 228 lbs. in the 
tops, consist of — 
^ ' ];ulb3. Tops. 
Ib^. lbs. 
Potasli 132 45^ 
Soda Gi- 7 
Magnesia 6i 2g- 
Lime 3C 68J 
Phosphoric acid 28f 11 J 
Sulphuric acid 36 25 
Silica 3 2^ 
Chloi ide of sodium 19 18f 
Chloride of potassium .. Hi 
Carbonic acid 47^^ 30;^ 
314 228 
An average crop of turnips thus removes from the soil 28J lbs. 
of phosphoric acid in the bulbs and 11^ lbs. in the tops, — 
39f lbs., or, in round numbers, 40 lbs. in all. 
The grain of wheat, on an average, contains 11 per cent, of 
ash, and wheat-straw 5 per cent. 
The mean produce of wheat per acre, talcen at 4 quarters, — 
32 bushels at 60 lbs. the bushel, is 1920 lbs. of wheat ; and 
as straw, being generally twice the weight of the grain, would 
weigh 3840 lbs.— 
lbs. 
In 1920 Ihs. of wheat there are 32;t of mineral matter. 
In 3840 lbs. of straw there are 192" „ 
Total mineral matter per acre 224A- 
According to the preceding analytical results, the mineral 
matters in the grain and straw of wheat per acre consist of — 
Wheat. Stmw. 
lbs. lbs. 
Phosphoric acid 9^ 
Sulphuric acid k 5f 
Silica 1 12bf 
Lime 1 lOh 
Magnesia 3^ 3f 
Potash 9J 25 
Soda 
Chlorides of potassium and sodiunj 
32i 192 
A fair average crop of wheat thus removes from the soil 1G\ lbs. 
of phosphoric acid in the grain, and 9i lbs. in the straw — together 
25f lbs., or in round numbers, 26 lbs. Therefore a turnip-crop 
weighing 20 tons per acre takes 14 lbs. more phosphoric acid 
out of the soil than 32 bushels of wheat and the straw belonging 
to it. 
