The Sources of the Nitrogen of our Leguminous Crops. 659 
Table I.— Estimates of the Yield and Gain of Carbon, and of the Increased 
Produce of Carhohydrates, per acre per annum, in various Crops. 
Carbon 
Carbohydrates 

For 1 lb. 
Actual Ciain 
Gain 
nitrogen 
in manure 
Mlieat twcnfi/ years, 1852-71. 
1 
Mineral mamirc ' 
„ „ and 43 lb. nitrogen as 
ammonia ...... 
Mineral manure and 86 lb. nitrogen as 
ammonia . 
Miaeral manure and 86 lb. nitrogen as 
lb. 
988 
1 1,590 
1 2,222 
i 2,500 
lb. 
602 
1,234 , 
1,512 
lb. 
1,240 
2,550 
3,140 1 
1 
lb. 
28 8 
29-7 
36-5 
Barley twejity years, 1852-71. 
Mineral manure 
„ „ and 43 lb. nitrogen as 
ammonia 
1,138 
} 2,088 
950 
1,992 
463 
Svgar-heet three years, 1871-73. 
Mineral manure 
„ „ and 861b. nitrogen as 
ammonia ...... 
Mineral manure and SO lb. nitrogen as 
nitrate 
1,123 _ _ 
1 2,600 ; 1,477 i 3,188 
I 3,031 j 1,908 ! 4,052 
^ 1 1 
37-1 
47-1 
Mangel-wurzel eight years, 1876-83. 
Mineral manure 
„ „ and 86 lb. nitrogen as 
ammonia 
Mineral manure and S6 lb. nitrogen as 
uitrate 
759 
1 1,889 
|- 2,129 
_ 
1,130 
1,370 
_ 
2,376 
2,771 
276 
32-2 
Potatoes ten years, 1876-85. 
Mineral manure 
„ „ and 86 lb. nitrogen as 
ammonia 
Mineral manure and 86 1'). nitrogen as 
nitrate 
1,021 
1 1,783 
j} 1,752 
763 
731 
l,i507 
1,416 
i 
17-5 
j 16-5 
Beans eight years, 1862 and 1864-70 
Mineral manure 
„ „ and 86 lb. nitrogen as 
uitrate ...... 
1 726 
i| 992 
r 
1 266 
j 474 
5-6 
X X 2 
