51 



water to the paste to bring the whole up to 25 gallons. When 

 the copper sulphate is entirely dissolved and the lime is cool r 

 pour the lime milk and copper sulphate solution slowly together, 

 using two buckets, each handled by a man, into a barrel holding 

 50 gallons. The milk of lime should be thoroughly stirred before 

 pouring. The method described insures good mixing, but to- 

 complete this work the barrel of liquid should receive a final 

 stirring, for at least three minutes, with a broad wooden paddle. 



It is now necessary to determine whether the mixture is- 

 perfect that is, if it will be safe to apply it to tender foliage. To- 

 accomplish this, two simple tests may be used. First insert the 

 blade of a penknife in the mixture, allowing it to remain there 

 for at least one minute. If metallic copper forms on the blade, or 

 in other words, if the polished surface of the steel assumes the 

 colour of copper plate, the mixture is unsafe and more lime mus& 

 be added. If, on the other hand, the blade of the knife remaint 

 unchanged, it is safe to conclude that the mixture is as perfect as- 

 it can be made. As an additional test, however, some of the 

 mixture may be poured into an old plate or saucer, and while 

 held between the eyes and the light the breath should be gently 

 blown upon the liquid for at least half a minute. If the mixture 

 is properly made, a thin pellicle, looking like oil on water, will 

 begin to form on the surface of the liquid. If no pellicle forms, 

 more milk of lime should be added. 



STOCK SOLUTIONS. 



The foregoing directions apply to cases where small quantittes 

 of the mixture are needed for more or less immediate use. If 

 spraying is to be done upon a large scale, it will be found much 

 more convenient and economical in every way to prepaie what 

 are known as stock solutions of both the copper and lime. To 

 prepare a stock solution of copper sulphate procure a barr* 1 hold- 

 ing 50 gallons. Weigh out 100 pounds of copper sulphate, and 

 after tying it in a sack suspend so that it will hang as near the top 

 of the barrel as possible. Fill the barrel with water, and in two 

 or three days the copper will be dissolved. Now remove the sack 

 and add enough water to bring the solution again up to the 50- 

 gallon mark, previously made on the barrel. It will be under- 

 stood, of course, thac this second adding of water is merely to 

 replace the space previously occupied by the sack and the crystals 

 of copper sulphate. Fach gallon of the solution thus made will 

 contain two pounds of copper sulphate, and under all ordinary 

 conditions of temperature, there will be no material recrystalliza- 

 tion, so that the stock preparation may be kept indefinitely. 



Stock lime may pe prepared in much the same way as the 

 copper sulphate solution. Procure a barrel holding 50 gallons, 

 making a mark to indicate the 50-gallon point. Weigh out 100 

 pounds of fresh lime, place it in the barrel and slack it. When 

 slacked, add sufficient water to bring the whole mass up to 50 



