148 INJURIOUS INSECTS OF I909 AND IQTO. 
For 40 or 50 gallons of spray take 11% to 2 pints of this solution, 
and 4 pounds of freshly slaked lime. Diulute the lime and strain, 
then add the quart of the stock solution. Pour into the spray bar- 
rel and it is ready for use. 
BORDEAUX MIXTURE. This is made of copper sulfate 
(blue stone), quick-lime and water. It is used in various strengths, 
the 5-5-50 being probably that in most common use, although the 
4-4-50 will probably give equally good results. 5-5-50 simply means 
that 5 pounds of copper sulfate, 5 pounds of lime and 50 gallons 
of water have been used in the preparation of the spray. In the 
same way 2-2-50 would mean that 2 pounds of copper sulfate, 2 
pounds of lime and 50 gallons of water have been used. The num- 
ber of pounds of copper sulfate is indicated by the first figure, the 
number of pounds of lime by the second, and the number of gal- 
lons of water by the third. 
One of two methods may be used in making bordeaux. Either 
it may be made directly or stock solutions may be made and these 
stock solutions used whenever the fungicide is needed. In making 
the spray directly, take 5 pounds of copper sulfate, put it into a 
coarse gunny sack and hang it in a barrel containing 25 gallons 
of water. Being suspended, the copper sulfate will dissolve much 
more readily than if put into the bottom of the barrel. Now slake 
carefully 5 pounds of good, quick lime, using just enough water to 
slake it slowly. Be sure that the lime is not all air-slaked. When 
the lime is slaked, add enough water to make 25 gallons. Now stir 
it carefully and then pour together the copper sulfate solution and 
the milk of lime. It is desirable to have a slight excess of lime, 
since it prevents any injurious action of the copper salts. If there 
is an excess of copper, foliage injury is liable to result. Therefore 
two simple tests should be made to determine whether or not the 
mixture is safe to use. Take a piece of newly-filed iron or steel 
and put it into the mixture for about a minute. If it has a copper 
coating when it is taken out, there is an excess of copper, and more 
lime should be added. To determine whether or not there is a 
sufficient amount of lime in the mixture, pour some of it into a flat 
dish and blow on it for a few moments. If a film forms on the 
surface, enough lime is present; if not, more should be added. In 
making stock solutions, dissolve copper sulfate in water at the 
rate of 1 pound to 1 gallon of water. Slake the lime slowly in 
another receptacle and, when slaked, add water until a thick, lime- 
milk,°5 pound to 1 gallon of water, is formed. When using the 
