244 Appendix. 



When large quantities of Bordeaux are required, it is most convenient to 

 make stock solutions pf lime and of copper sulphate of known strength. A con- 

 venient stock solution of copper sulphate is made by dissolving one hundred' 

 pounds in fifty gallons of water ; one of lime, by slaking cue hundred pounds 

 and diluting with water to fifty gallons. Each gallon of the stock solution will 

 then contain two pounds of lime or of copper sulphate and the amount to be 

 used in preparing any quantity of Bordeaux according to the above formulas can 

 be readily computed. 



If sufficient lime has not been used, or if that used was of an inferior 

 quality the Bordeaux may injure the foliage or may cause a "russetting" of the 

 fruit. It is, therefore, always best to determine whether enough lime has been 

 used by testing the mixture. 



Testing Bordeaux. 



There are three simple tests which may be used. First, hold a clean, bright 

 knife blade in the Bordeaux for at least one minute. If it becomes copper- 

 plated more lime should be used. Second, pour some of the Bordeaux into a 

 shallow dish and holding it up to the light blow gently across its surface. If 

 properly made a thin pellicle will form on the surface of the liquid. If this 

 does not form more lime should be added. Third, dissolve one ounce of fer- 

 rocyanide of potassium in five or six ounces of water. Pour some of the 

 Bordeaux into a white dish and add to it a few drops of the ferrocyanide solution. 

 If suflicient lime has been used no change will be noticed. If a brownish-red 

 discoloration takes place more lime should be added. 



One gallon of resin wasli No. 14 to three gallons of Bordeaux is said tO' 

 make the mixture more adhesive. 



24. Copper Sulphate Solution. 



A simple solution of copper sulphate is used as a remedy for grain smut& 

 and sometimes as a spray in place of Bordeaux. For dormant trees use. 



Copper sulphate 1 pound 



Water 25 gallons 



For trees in foliage use 



Copper sulphate 1 pound 



Water 250 gallons 



For smut of wheat or oats, soak the seed for ten or twelve hours in a 

 solution of one pound of blue vitrol to twenty-five gallons of water, then put 

 the seed for five or ten minutes into lime water made by slaking one pound 

 of lime and diluting it with ten gallons of water. 



The treatment with lime water tends to prevent the copper sulphate solu- 

 tion from injuring the seed, but many farmers omit that part of the treat- 

 ment. 



Bordeaux mixture has the disadvantage that it produces an unsightly de- 

 posit upon foliage, blossoms and fruit, and hence can not well be used upon 

 florists' plants or upon fruits nearly ready for market. For use under such con- 

 ditions the ammoniacal copper carbonate, the simpler copper carbonate mixture 

 or the copper acetate solution is recommended. 



25. Ammoniacal Coppek Carbonate. 



Copper carbonate 5 ounces 



Strong ammonia 3 pints 



Water - .., 50 gallons 



Mix the copper carbonate into a paste with a little water, add the ammonia 

 and when the copper carbonate is completely dissolved pour the resulting deep' 

 blue liquid into the water. 



