The Sources of the Nitrotjcu of our LeijamiTWUs Crojjs. 661 
per acre, and by 86 lb. as sodium-nitrate 731 lb. That is to 
say, there was considerably less increased production of starch 
in potatoes than of sugar in sugar-beet or mangel-wurzel, by 
the same applications of nitrogenous manure. 
Lastly, in the leguminous crop — beans, with its high yield 
of nitrogen per acre, and the high percentage of nitrogen in its 
dry substance — the increased assimilation of carbon under the 
influence of nitrogenous manure was, comparatively, quite insig- 
nificant. Thus, there was, by the application of 86 lb. of 
nitrogen as sodium-nitrate, an increased assimilation of carbon 
of only 2GG lb. per acre; or little more than one-sixth as much 
as in wheat, and little more than one-eighth as much as in sugar- 
beet, by the same application. 
Turning to the figures in the third column of the Table on 
page G59, it is seen that there was a very greatly increased 
production of the non-nitrogenous bodies — the carbohydrates — 
by the use of nitrogenous manures. 
Thus, by the use of 43 lb. of nitrogen as ammonium-salts, 
there was an estimated increase of 1,240 lb. of carbohydrates in 
the grain and straw of wheat, and of 1,992 lb, in those of 
barley. By the application of 86 lb. of nitrogen as ammonium- 
salts, there was an increased formation of 2,550 lb. of carbo- 
hydrates in wheat, of 3,188 lb. in sugar-beet, of 2,376 lb. in man- 
gel-wurzel, and of only 1,5071b. in potatoes; and when 861b. 
were applied as sodium-nitrate, there was an increased produc- 
tion of 3,140 lb. in wheat, of 4,052 lb. ir. sugar-beet, of 2,771 lb. 
in mangel-wurzel, and of only 1,416 lb. in potatoes; whilst, 
compared with these amounts, there was in beans, by the same 
application, an increase of only 474 lb. of carbohydrates. 
The last column shows the estimated increased amounts of 
carbohydrates produced, for 1 lb. of nitrogen supplied in manure, 
in the different cases. Thus, when 43 lb. of nitrogen were applied 
as ammonium-salts, 1 lb. of nitrogen in manure gave an in- 
creased production of 28'8 lb. of carbohydrates in the grain and 
straw of wheat, and of 46 3 lb. in those of barley ; when 86 lb. 
were applied as ammonium-salts, 1 lb. gave an increase of 29*7 lb. 
carbohydrates in wheat, 37'1 lb. in sugar-beet, 27"6 lb. in 
mangel-wurzel, and 17"51b. in potatoes. Again, when 86 1b. 
were applied as sodium-nitrate, 1 lb. gave an increase of 36-5 lb. 
carbohydrates in wheat, 47'1 lb. in sugar-beet, 32-2 lb. in 
mangel-wurzel, 16-5 lb. in potatoes, and only 5'5 lb. in the 
leguminous crop — beans. 
Thus, then, we have the apparently anomalous result, that 
the crops which are characterised by yielding a comparatively 
small amoant of nitrogen oyer a given area, by containing a corn. 
