212 The Principles of Vegetable -Gardening 



If not done after slaking, the lime should now be diluted to 

 make ten to fifteen gallons of "milk of lime." This is poured 

 into the spray barrel and unites with the vitriol solution to make 

 Bordeaux. It should preferably be poured into the barrel through 

 a screen of some sort to take out the unslaked lumps, which 

 would clog the nozzle. A piece of wire fly screen or a double 

 thickness of coarse potato burlap is excellent. Fertilizer sacking 

 is too fine meshed for this purpose. It is not wise to mix the 

 vitriol solution and the milk of lime when less dilute than this; 

 otherwise the Bordeaux is more likely to burn the foliage and 

 is lumpy. Fill the barrel with water to make fifty gallons, and 

 stir the mixture thoroughly for a few minutes. If there is no 

 automatic agitator attached to the pump, the mixture should be 

 thoroughly stirred with a paddle while spraying at least every 

 five minutes. 



Bordeaux itself should always be made fresh for each spray- 

 ing, as it deteriorates on standing; but the vitriol solution and 

 slaked lime may be kept on hand ready for mixing. When 

 much spraying is to be done it generally saves time to make a 

 stock solution of the vitriol and slake a quantity of lime before 

 hand. Thus forty pounds of vitriol may be dissolved in forty 

 gallons of water. Each gallon will then contain one pound of 

 vitriol, and four gallons will be needed to make fifty gallons 

 of Bordeaux. The stock solution of vitriol must be kept tightly 

 covered to prevent evaporation. A good plan is to sink the 

 barrel containing it in the ground. 



Likewise forty pounds of lime may be slaked in forty 

 gallons of water and used like the vitriol; or it may be slaked 

 to the consistency of putty, spread evenly over the bottom of a 

 narrow trough, and covered with water to exclude air. Knowing 

 the number of pounds of lime in the trough, a certain fraction 

 of its area will contain the four pounds needed for a barrel, and 

 this is separated off at one end when needed. 



Instead of measuring the lime it is often more convenient 

 to use the ferro-cyanide test when large amounts are slaked 

 beforehand. An ounce of potassium ferro-cyanide may be 

 bought in any drug store, and will be sufficient for a season. 



