12 



.025%, .01% and .005% of chromium were shown to be fatal to 

 barley, whether chromate or bichromate was used, and that in the 

 second year only the .025% proved still harmful to wheat, any 

 injurious effect from .01% and .005% havings passed off. Now in 

 the third year, wheat being again sown, the .025% also lost its 

 ill effect, and exercised, as did the lower amounts, a slightly 

 stimulating influence. 



2. — ^The fresh experiments started in 1921 with chromate and 

 bichromate of potash, and also with chromic acid, were continued 

 in 1922 with a second wheat crop. In 1921 it had been found that 

 .005% of chromium was not a safe amount to use, whether as 

 chromate or bichromate of potash or as chromic acid, but that 

 smaller amounts of .0025% and .001% exercised a decidedly 

 stimulating influence. On continuing, without further additions, 

 for a second wheat crop in 1922, the results showed that a marked 

 increase of crop was obtained from the .005% application (which 

 the year before had been destructive), and a like, but decreasing, 

 benefit from the smaller applications. 



Putting together the results of 1 and 2 as here described, the 

 general conclusion is reached that, while .005% of chromium is 

 not a safe amount to have in a soil for the first year of growth of 

 a corn crop, smaller quantities will not prove harmful, but rather 

 stimulating, and that .005%, and even .01%, will lose its injurious 

 effect in a second year, and .025% in a third year, a stimulating 

 influence taking then the place of a previously harmful one. 



The changes shown in the first 2 years may be illustrated by 

 the accompanying curves obtained with potassium bichromate. 



II. The Relative Effects of Lime and Chalk, 1922. 



This experiment, a duplicate, in pot-culture, of the field experi- 

 ment in Stackyard Field (Series B) started in 1919, was continued 

 for a fourth year, no further additions being given, and wheat 

 being sown again on October 26th, 1921. 



Lime, it may be recalled, was given at the rates of 10 cwt., 

 1 ton, 2 tons, 3 tons, and 4 tons per acre respectively, and chalk 

 to supply the same amounts of lime (CaO). The results obtained 

 were very similar to those of 1920, and in the following table the 

 figures for the 4 years are collected. 



