400 F. B. GUTHRIE AND R. HELMS. 



the germination was slightly affected, and in 166 and 167 the 



germination was very weak — in pot 167 the plants hardly 



germinated. In all cases, even in pots 163 and 161, the 



subsequent growth was very feeble and the plants were 



nearly dead. In pots 166 and 167 the plants were quite dead. 



Two more pots were therefore sown on October 10th 



with smaller quantities of NaC10 3 in order to determine 



the point at which the growth commenced to be affected. 



No. 168, *001 per cent. Na01O 3 



„ 169, '002 



These pots were examined in October 21st, when both 

 had germinated well. In pot 168 the growth was unaffected 

 and in No. 169 the growth was slightly affected. By 

 December 1th, when the pots were again examined, the 

 plants in hot Ii cases had recovered and were growing well. 



From these it is concluded that germination is unaffected 

 by NaClO., in the case of rye by quantities below *004 per 

 cent., tin- presence of '006 per cent, preventing germin- 

 ation. The subsequent growth of the plants is affected by 

 *002 per cent., but under favourable conditions the plants 

 can recover. Growth is prevented by "001 per cent. 



Experiments ivitJi arsenious acid. 



The following 5 pots were filled with soil, manured and 



sown on August 6th with varying quantities of arsenious 



acid : — 



No. 170, *05 per cent. As,O s 



,, 171, *10 ,, ,, 



„ 172, -20 



,, l/o, oO ,, ,, 



„ 174, '40 



When examined on August 21st, the following appearances 



were noted: — In pots Nos.170 and 171 the plants germinated 



freely. In 172 the germination was retarded. In 173 and 



174 the germination was very feeble, and in No. 174 the 



