No. 4.] POTATO (JUOWING. 3(37 



Formulas for Blujhts, — Bordeaux Mixture. 



Formula 6. 



Copper sul pi Kite, ....... 5 pounds. 



Fresh lime (unshiked), ...... 5 pounds. 



Water, ......... 50 gallons.' 



P'OUMULA Ga. 



Copper sulphate, ....... 5 pounds. 



Hydrated lime (prepared or ground lime), . . . 6-7 poimds. 



Water, ......... 50 gallons.' 



Bordeaux niixtiiro according to Formula 6 is prepared as follows: — 

 the copper sulphate is tlissolved and the lime slaked in separate vessels. 

 A wooden or earthen vessel must be used for the copper sulphate, as 

 it corrodes iron. Each solution should then be diluted with half 

 the water, and then the cold, dilute sulphate and milk of lime solution 

 quickUj united and thoroughly mixed. Never pour concentrated solu- 

 tions together. If impracticable to pour the two dilute solutions into 

 the sprayer or mixing tank simultaneously, the dilute copper sulphate 

 solution should be first placed in the tank and the dilute milk of lime 

 solution (juickly added with constant stirring. 



Best results are obtained if care is taken to add the water slowly 

 to the lime while slaking, but it should not be allowed to become 

 dry. The milk of lime must be strained, and this is best done while 

 still hot. A brass wire strainer of about 30 meshes to the inch (No. 50), 

 or a piece of cheese cloth backed by common window screen, may be 

 used. The best type of strainer can be made by nailing together 

 four 1-inch boards about 7 or 8 inches wide and 12 or 15 inches long, 

 making a box open at both ends. One end of the box is then cut off 

 at a considerable angle, leaving one side shorter than the other. No. 

 50 brass wire strainer is tacked on to this end. Two cleats are nailed 

 to the other end of the box, long enough to more than reach across 

 the top of the barrel. When placed on top of a bawel with the wire 

 bottom down, all the solid particles from the solution are washed to 

 the lower side of the screen, thus avoiding clogging the whole surface. 



The most convenient method of preparing Bordeaux mixture is to 

 make stock solutions. For this purpose suspend 100 pounds of copper 

 sulphate in a bag near the top of a 50-gallon barrel and fill with water. 

 This should dissolve over night. In another 50-gallon barrel slake 

 100 pounds of stone lime, dilute and strain and make up to 50 gal- 

 lons. A gallon of each solution well stirred will be equivalent to 2 

 pounds of copper sulphate or Ume, as the case may be. For a 50- 

 gallon tank of mixture the stock solution should be thoroughly stirred, 

 and then 2\ gallons of each dipped out, diluted and mixed as de- 

 scribed above. For a 100-gallon tank 5 gallons of each stock solu- 

 tion is used, and each diluted to 50 gallons before mixing. 



' Axi ordinary oil barrel holils about 50 gallons. 



