FUNGICIDES, FOR PLANT-DISEASES. 49 



pound of carbonate of soda. Mix the two solutions. 

 When chemical reaction has ceased, add 1^ pints of ammo- 

 nia, then dilute to 25 gallons. For the same purposes as 

 No. 1, and better. 



Grison liquid (Eau Grison). — Prepared by boiling 3 pounds 

 each of flowers of sulphur and lime in 6 gallons of water 

 until reduced to 2 gallons. When settled, pour off the 

 clear liquid and bottle it. When used, mix 1 pint of clear 

 liquid in 100 parts of water. For European mildew and 

 powdery mildew of vines. 



Podeschard's powder. — Dissolve 45 pounds of sulphate of 

 copper in water. When thoroughly dissolved, pour the 

 solution upon 225 pounds of air-slaked lime, which is sur- 

 rounded by 30 pounds of ashes to keep the liquid from 

 spreading. After 24 houys add 20 pounds of flowers of 

 sulphur. Thoroughly mix the compound, ashes and all. 

 When dry, sift through a sieve with meshes of one-eighth 

 inch. Will keep for months. For downy mildew, mildew 

 and anthracnose. 



Potassium sulphide. — See Sulphide of Potassium. 



Rotation of crops is one of the most effective and prac- 

 ticable means of heading off fungous diseases. It may be 

 applied to strawberries for the leaf-blight, by fruiting the 

 patch but a single year, and to blackberries and raspberries 

 by destroying the patch after two or three crops have been 

 harvested. 



Sulfo-steatite, or Cupric steatite. — An exceedingly fine blu- 

 ish powder composed of steatite, or talc, and about 10 per 

 cent of sulphate of copper. Considered the most adherent 

 of all fungicide powders. Is often injurious to foliage and 

 should be applied with care. For mildews. 



Sulphate of copper (Blue Vitriol). — 1. Dissolve 1 pound of 

 pure sulphate of copper in 15 gallons of water. For downy 

 mildew and black-rot of grape and apple-scab in winter, or 

 in spring before the buds swell. Use 25 gallons water for 

 peaches. Should be applied only to dormant wood. 



2. Dissolve 5 to 8 pounds in 10 gallons of water. For 



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