New YorK AGRICULTURAL EXPERIMENT STATION. 177 
Average total cost** of spraying per acre (23 experiments), 
$3.91. 
Average cost per acre for each spraying (23 experiments), 
90 2-3 cents. j | 
Average market price of potatoes at digging time, 4314 cents 
per bushel. 
Average net profit per acre (23 experiments), $22.01. 
AN EXPERIMENT TO DETERMINE THE RELATIVE EFFI- 
CIENCY OF SOLUBLE BORDEAUX, SODA BORDEAUX 
AND LIME BORDEAUX FOR THE PREVENTION OF 
POTATO BLIGHT, PHYTOPHTHORA INFESTANS. 
INTRODUCTION. 
Soluble bordeaux.—At the request of Director W. A. Henry of 
the Wisconsin Experiment Station we made a test of the “ soluble 
bordeaux” devised by Dr. S. M. Babcock of the same Station. 
Concerning the preparation and use of soluble bordeaux Dr Bab- 
cock gave us the following instructions: 
Stock Solutions. 
1. Copper sulphate solution: 
Dissolve one pound of copper sulphate in two gallons of cold water. Will 
keep indefinitely. 
2. Solution of sucrate of lime: ‘ 
Slake ten pounds of fresh lime in 30 pounds of water, strain the milk 
of lime through a wire strainer and add a solution of 25 pounds of granulated 
sugar in 50 pounds 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 eight 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 eonsiderable 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 1 and 2 and add three parts of water. Agitate 
until the copper hydrate which is at first precipitated is entirely dissolved. 
“‘In every one of the 23 experiments which enter into this average the 
cost given includes both labor and materials and in most cases also poison 
for bugs and an allowance for the wear of machinery. 
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