J. V. EvRE AM) E. S. Salmon 503 



Exper. 10, Siiliih'oii roii/niiiiHi/ (1-1")"^ iron sulphide uiid 1 °\, soft 

 son p. 



Ixl ihiij. All the patclics of mildew completely covered by the spray and 

 apparently killed; no injury to the leaven apparent. 



M ilay. All the patches of mildew dead; the youngest sprayed leaf showing 

 injury at the tip and margin. 



&h iliii/. The youngest leaf iiuw severely injured; the remaining leaves 

 unatfecterl. 



9/// iliii/. Xo finther injury to the leaves. 



Exper. 11. Soluliot cuiitainitig 0-9 % iron sulphide and 1 % soft 

 soap. 



Isl day. All the patches of mildew completely covered by the spray and 

 apparently killed ; the youngest of the sprayed leaves injured and shi'ivelled. 



itii day. All the patches of mildew dead ; injiny apparent to the tip and margins 

 of another leaf — the remaining leaves (four) not injnred. 



Qth day. Xo further injury to the leaves. 



Suinnwri/ of Ohsprratioiis. VIIT. 



The iron sulphide solution dries at once to a rusty-brown deposit 

 which covers over uniformly the patches of mildew^. A 0-3 % solution, 

 with a 1 % solution of soft soap, is almost satisfactory as a fungicide; 

 a 0-6 % solution, with either a 0-5 % or 1 % solution of soft soap, is 

 invariably fungicidal. No injury was caused to the foHage. In the above 

 experiments the iron sulphide was made by the method (i) (described 

 at p. 480) under which it was possible for a small quantity of ammonium 

 sulphide to be present. In two experiments (carried out in 1915) the 

 iron stilphide was made on the method (ii) (described at p. 480) under 

 which no ammonium sulphide was present. In the first experiment 

 (No. 10) a 0-4-5 % solution of iron sulphide was used : it proved 

 completely fungicidal by the 4th day. Severe injury was caused to 

 the youngest Hop-leaf, the others remaining uninjured. In the second 

 experiment (No. 11) a 0-9 % solution was used; the mildew was killed 

 immediately; two out of the six leaves were injured at the tips and 



' If used on Gooseberries it would be inferior to the yellow ammonium sulphide solution 

 because it would disfigure the berries; it wo>dd have the advantage, however, over 

 lime-sulphur in that the markings on tlie sprayed berries would not be liable to be mistaken 

 for spots of mildew by incompetent inspectors at the market. 



