I 
INTRODUCTION 
II 
make up the 50 gallons, the resulting Bordeaux mixture will be 
of very inferior quality. 
The method of mixing described above is that recommended 
by all scientific authorities in the United States and in our 
Colonies. Bordeaux mixture prepared by growers in accordance 
with these instructions has long proved in these countries to 
be of the greatest value, under practical conditions in the 
orchard and plantation, in keeping off fungus pests from 
cultivated plants. According, however, to the recent important 
investigations of Mr. S. U. Pickering into the nature of 
Bordeaux mixture, a slightly superior method of mixing the 
two constituents is “ to take the lime in as weak a condition 
as possible and, consequently, the copper sulphate in as strong 
a condition as possible, and to add the copper sulphate to the 
lime. The ‘ milk-of-lime,’ after being diluted with the bulk of 
the water and stirred up several times during about half an 
hour, should be left for the grosser particles to settle before 
the copper sulphate is added to it, and, after the addition of this, 
very little more stirring should be done.” 
Bordeaux mixture is fully efficacious only when freshly 
made, and will not keep. If more than a day old, it requires to 
be very thoroughly and constantly stirred while being used, 
and the use of only freshly -made Bordeaux mixture is far more 
economical in the long run, and is here strongly recommended. 
If a considerable quantity of Bordeaux mixture is required 
for use, the making of stoch solutions of copper sulphate and 
lime, which can be kept through the spraying season and used 
when wanted, saves both time and labour, and is free from all 
objections. The stock solutions are made as follows : take 
two 50-gallon barrels. In one dissolve 50 lb. of copper sulphate 
in exactly 50 gallons of water. In the other slake 50 lb. of 
lime by the gradual addition of a little water; to the creamy 
paste thus obtained add water to make exactly 50 gallons of 
“milk-of-lime.” These stock solutions will keep for months. 
Before the “milk-of-lime” is used, the contents of the barrel 
must be thoroughly stirred, as the slaked lime will have sunk to 
the bottom. (Care must be taken to stir the “milk-of-lime” 
rery thoroughly each time before measuring it out, so as to get 
the slaked lime thoroughly in suspension. If this is done there 
is no difficulty in obtaining the correct quantity of lime per 
gallon of fluid.) Each gallon which is taken out from the 
“ stock solutions ” will be equivalent, respectively, to 1 lb. of 
copper sulphate or 1 lb. of lime. The required amount of each 
stock solution is then diluted with water, according to the 
formula given above, before being mixed together. The “ stock ” 
