New York AGRICULTURAL EXPERIMENT STATION. 707 
A solution containing sixty-nine grams of copper sulphate per 
litre after standing in a corked bottle about ten weeks was 
tested and the top showed 1.0365 specific gravity, while the 
bottom showed 1.0550 specific gravity, making a difference of 
0.0185 between the two. But a solution containing two pounds 
of copper sulphate per gallon after standing a week showed 
practically no difference between the top and bottom as to 
strength of the solution. It seems therefore that for all practical 
purposes a solution containing two pounds of copper sulphate per 
gallon may be safely used for stock solution.* It would take 
two gallons of such a solution to make forty-five gallons of the 
Bordeaux mixture according to the formula given on a previous 
page. 
Spraying in rainy weather.— If Bordeaux mixture has time to 
dry after it is applied to the foliage it will take a good deal of 
rain to wash it all off. Ordinarily, when the proper time for 
spraying has arrived, it is best to do the work even though there 
are prospects of rain, for in many such instances either very little 
rain falls or perhaps none at all, and if the spraying is done the 
full benefit of the treatment is secured. In following this plan it 
occasionally becomes necessary to repeat the spraying after a 
heavy rainfall, but the time spent in such instances in making 
an extra spraying will be much less than the time wasted when 
_ the opposite course is pursued and the spraying postponed when- 
ever the clouds threaten rain. 
Nozzles.— In recent years many good nozzles for applying 
- fungicides and insecticides have been devised, but it is generally 
_ conceded that for the application of Bordeaux mixture nothing 
has yet been found that equals the Vermorel. Various forms of 
this nozzle are on the market, some of which have no joint 
between the nozzle chamber and the elbow. Occasionally some 
obstruction lodges between the elbow and the nozzle chamber, 
and therefore it is best to select those forms of the Vermorel 
which have a joint at this place, so that the part containing the 
nozzle chamber may be easily separated from the rest of the 
nozzle and any obstruction removed. 
The Vermorel nozzle is capable of giving an exceedingly fine 
spray, which is most desirable, but it can throw the spray but a 
*See Solutions by W. Ostwald, translated by Muir, 1891, ‘‘ Homogeneousness of solutions,”’ 
pp. 148 to{151. 
