GREEN VITRIOL. 185 



polypores and against anthracaose. All the parts of the wood attacked 

 and coloured around the canker muot be removed by cutting, t'oi' even 

 apparently healthy parts may contain ramifications ot the mycelium. 

 By carefully moistening these bared parts with the corrosive solution 

 of green vitriol and sulphuric acid, the cankers are cured. 



Dasyscijjiha Wilkovimi, Hartig (canker of the larch). — Prill ieux 

 recommends to destroy this fungus which belongs to the Pezizes the 

 same treatment as the Xectria ditisswia. 



Clav iceps ptirpivrea, Tul. (ergot of rye). — The spores of this fungus 

 are those which resist immersion for the longest lime even in con- 

 .centrated solution of green vitriol. Solutions of 1-10 per cent have 

 no action on them. In spite of that McAlpine recommends to 

 rprevent and combat this disease a 1-4 per cent solution. The spores 

 do not find on the cereals strengthened by this ferruginous treatment 

 the soil favourable to their growth, and the less number of diseased 

 plants is due to the improvement in their power of resistance of both 

 healthy and attacked plants. 



Dematophora )ieca.trix, Hartig (white root rot). — Dufour tested 

 ■comparatively the action of green vitriol and blue vitriol on this fungus, 

 and found the latter much superior to the former. However, Beniling 

 and Behaix recommend green vitriol against rot of vine roots ( Wurzel- 

 •schimmel) where carbon disulphide and sodic fluoride had no action. 



Bhizoctinia violacea, Tul. (rhizoctinia of lucerne and beet). — Bu- 

 back tried to contend against this fungus by spreading 4 kilogrammes 

 (8 '8 lb.) of green vitriol on a plot of ground 10 square metres, then sow- 

 ing beets eight days later after burying the green vitriol. The result was 

 that the iron salt greatly stimulated the growth of the beets, increased 

 the sugar, and that the plot had only 28 per cent of diseased plants 

 against 47 per cent in the check plot. 



Gloeosporiimi amjjelophagmn (grape rot). — Sulphuring and treat- 

 ing the vine with cupric bouillies have not circumscribed this disease 

 at the same time as the oidium and mildew. Anthracnose must be 

 treated by itself, and only winter treatment with green vitriol has 

 proved entirely satisfactory. Schnorf was the first to advise and use 

 50 per cent solutions of green vitriol to contend against this disease, 

 and Skawinski was the first to add to these solutions a small amount 

 of sulphuric acid to render the solutions more corrosive. This last 

 formula has given perfect results. Studied in different countries, this 

 mixture has undergone some alterations of no importance. Sorauer 

 advises a 40 per cent solution. Tome a 35 per cent, Ghirardi from 

 ■0'5-2 for young shoots, so as to prevent scorching by stronger doses. 

 Bolley advises 50 per cent of green vitriol and 5 per cent of sulphuric 

 acid ; Galloway 6 per cent of green vitriol and 0'45 per cent of 

 sulphuric acid; Scribner 23-6 per cent of green vitriol, 6-6 per cent 

 of blue vitriol, and 19 per cent of sulphuric acid; Thomas 20 per 

 ■cent of green vitriol, 14 per cent of blue vitriol, and 12 per cent of 

 fat lime ; finally, Orillard 25 per cent of green vitriol and 10 per cent 

 ■of blue vitriol. 



Contrary to the opinion of Berlese, who attributes the success of 

 these mixtures to their (free) sulphuric acid content, alone capable in 



