THE BORDEAUX MIXTURE =53 



For convenience in weighing, 35^ lbs. of lime may be used. 

 This makes what we have designated as a i to 10 mixture. 

 The one described below by Mr. Galloway is a i to S}( mix- 

 ture. It will not do to throw these ingredients together hap- 

 hazard and expect a good result. The blue vitriol should be 

 dissolved separately ; this can be done with cold water, but it 

 requires considerable time and is best done in the way described 

 by Mr. Galloway. Wiien wanted for immediate use, it may 

 be dissolved rapidly in hot water, two quarts of which will 

 dissolve a pound. A good way is to prepare a stock solution 

 in quantity beforehand, making it of such strength that a half 

 gallon or a gallon will contain one pound. 



Only fresh lime should be used. Select the firm, uncrum- 

 bled lumps. Slack it by adding water slowly, just enough to 

 keep it from burning or becoming dry until tlie lumps are all 

 broken up, then add water enough to make a thin paste. The 

 method of mixing the solution of blue vitriol and the lime rec- 

 ommended by Galloway is the ideal one, and even when it is 

 not convenient to follow it in detail, the principle involved 

 should be followed ; that is, to dilute both the blue vitriol and 

 the lime as much as possible before mixing. 



If the quantity oi fresh lime given in the formula be used, it 

 will not be necessary to test the mixture. But it is often con- 

 venient to make up a considerable quantity of lime paste, and 

 inconvenient to measure it afterwards ; then a test which will 

 tell when enough lime has been used will be convenient. 



Dissolve a lump of yellow prussiate of potash (which may 

 be obtained at any drug store) as large as a chestnut in a gill 

 of water, and keep in a bottle; add a few drops of this to a 

 saucerful of the prepared mixture. If a brown color appears, 

 add more lime to the mixture, and test again. When sufficient 

 lime has been used, no brown color will appear on applying 

 the prussiate solution. Other tests are given below. 



The following explicit directions for making the Bordeaux 

 mixture were written by Mr. B. T. Galloway, of the United 

 States Department of Agriculture : In a barrel or other suitable 

 vessel place twenty-five gallons of water. Weigh out six 

 pounds of copper sulphate, then tie the same in a piece of 

 coarse gunny sack, and suspend it just beneath the surface of the 



