SOLUBLE BORDEAUX FOR POTATO BLIGHT. 9 



possibly fifty times and still protect plants from the ordinary 

 fungus diseases. In addition to this advantage, the absence of 

 solid particles permits the use of a much finer spray than is now 

 employed, and it is evident that with a fine spray much more 

 surface can be covered with the same amount of material. In 

 these two ways it is hoped that the expense for the materials 

 used in spraying may be greatly reduced." 



The soluble Bordeaux used in the experiments here reported 

 was prepared in accordance with the following directions fur- 

 nished by Dr. S. M. Babcock, chemist to the Wisconsin Agricul- 

 tural Experiment Station. 



PREPARATION OF SOLUBLE BORDEAUX. 



1. Copper sulphate solution — Dissolve i lb. of copper sul- 

 phate in 2 gallons of cold water. Will keep indefinitely. 



2. Solution of sucrate of lime — Slake 10 lbs. fresh lime in 30 

 lbs. of water, strain the milk of lime through a wire strainer and 

 add a solution of 25 lbs. of granulated sugar in 50 lbs. of water. 

 Stir thoroughly at frequent intervals, and after two or three 

 hours decant or siphon the clear liquid from the undissolved 

 lime. The lime and sugar solution can be conveniently mixed 

 in a revolving barrel churn. 



The quantities named are sufficient for about 8 gallons of 

 standard solution of sucrate of lime. 



The solution will keep indefinitely if placed in well stoppered 

 bottles, but if open to the air will gradually absorb carbonic acid 

 gas and the lime will separate. 



After siphoning off the clear solution, the residue still contains 

 some sugar which may be recovered by adding considerable 

 water and allowing the residue to settle a second time. The 

 clear solution obtained may be used in place of an equal quantity 

 of water in the preparation of the next lot. 



SOLUBLE BORDEAUX. 



Take equal parts of solution i and 2 and add three parts of 

 water. Agitate until the copper hydrate which is at first precip- 

 itated is entirely dissolved. Upon standing, a slight deposit of 



