LIMITS OF ENDURANCE OF DIFFERENT FARM CROPS. 401 



plants had hardly germinated at all. The plants were 

 growing well in No. 170, but the growth was already affected 

 in No. 171, and in the remaining pots the plants were very 

 feeble and in 173 and 174 nearly dead. 



Subsequent examination of the pots on October 10th 

 showed the plants in No. 170 to be growing normally and 

 equal to the check-pots. The plants in No. 171 had recovered 

 and were apparently quite as healthy as those in the check- 

 pots. In No. 172 the growth was affected (stunted) and in 

 173 and 174 the plants were dead. 



The conclusions drawn are that germination in the case 

 of rye is unaffected by quantities of arsenic below '2 per 

 cent. With "2 per cent germination is affected, and about 

 *4 or a little over prevents germination. The subsequent 

 growth of rye is not affected until the amount of arsenic in 

 the soil reaches *15 per cent, at which point the effects of 

 its presence are marked, and with *30 per cent, the growth 

 of rye is prevented. 



The results of the experiments with rye are presented 

 in the following table : — 



Effect upon germination and subsequent growth of Rye of different 

 percentages of injurious substances in the soil. 



NaOl 



Germination Germination 

 affected prevented 



•10 -40 



Growth 

 affected 



•15 



Growth 

 prevented 



•20 



Na 2 C0 3 



•25 -50 



•25 



•40 



NKUCNS 



inconclusive 







NaC10 3 



•004 -006 



•002 



•004 



As 2 3 



*2 above *4 



•15 



•30 



Z— Nov. 7, 1904. 



