W. F. Bewley 169 



readily. Two heaps were made, each of 60 lbs. ; one was left untreated 

 and into the other was gradually worked 2 gallons of a 2 per cent, 

 solution of formalin, the whole being thoroughly mixed with a spade. 

 It was then covered with sacking for 48 hours, after which the sacking 

 was removed and the heap spread out and allowed to dry. Fourteen days 

 after treatment, nine boxes and six pots were filled from each heap. The 

 boxes were sown with sterile seed and the pots planted with young 

 healthy seedlings reared in sterilised soil. In each case sterile water was 

 used for watering. The treated soil produced plants free from disease, 

 while the untreated soils in the nine boxes showed an average of 48 per 

 cent, of diseased plants and five pots out of six contained plants affected 

 with "foot-rot." 



The time after treatment at which it is safe to sow. 



Twenty-four boxes were made up with naturally infected soil. 

 Twenty were treated with a 2 per cent, solution of formalin, covered, 

 and sown in pairs on successive days. One hundred seeds were sown per 

 box, and the infected seedlings were removed as soon as they were 

 attacked. 



Table IX. 



The untreated controls showed an average of 44 per cent, diseased 

 seedlings per box. 



In this experiment it was safe to sow from four to seven days after 

 treatment, but in practice it is better to allow a fortnight interval for 

 the vapours to pass completely out of the soil. 



Treatment after disease has appeared. 



Numerous attempts have been made to stop the disease once it has 

 become established in the seed-box. In our experiments, the diseased 



