74 THE SAX JOSE OR CHINESE SCALE. 
A year later (1901-2) very elaborate tests conducted by Doctor Forbes 
in Illinois showed that fairly hard rains will not always invalidate 
spraying with this mixture. A vast amount of experience of the most 
practical kind since gained, contributed to by all the eastern experi- 
ment station- and by the big commercial fruit growers of the Middle 
and Eastern States, has fully demonstrated the practical merit of this 
wash and it- superiority to others in point of safety to tree< and in 
cheapness. The wash i- furthermore a valuable fungicide and is nota- 
bly useful against the peach leaf curl, sprayed trees being practically 
immune from this disease, so that the cost of treatment i- often more 
than made o-ood by the fungicidal benefit alone. Its disadvantages are 
the difficulty of preparation and the heavy wear which it entails on 
apparatus — objections, however, which do not offset its notable advan- 
tage-, particularly for commercial orchard work or where the number 
of trees to be treated is sufficient to warrant the trouble of its prepara- 
tion. It is, in fact, the standard spray now used in commercial orchards 
for the San Jose scale. 
In the matter of composition of the wash scarcely any two experi- 
menters agree. Salt was a part of the original composition of the sheep 
dip and has long been retained, with the idea that it added, perhaps, to 
the caustic qualities, and particularly to the adhesive, nature of the 
wash. For the latter purpose a very small amount only. 1 or '2 pounds 
to the bushel of lime, need be added, following the custom in the 
preparation of whitewash mixtures. In practical experience, however, 
the salt seems to have been of very little benetit and i< therefore 
omitted in the formula now given. The proportion of lime and sulfur 
is a matter of some indifference. The mixture obtained i- sulphide of 
lime, and if an excess of lime is used it -imply remain- undissolved in 
the mixture and adds to the whitewashing character of the application. 
Too much lime is distinctly objectionable, however, because of the 
greater difficulty of spraying and harder wear on the pump and nozzles. 
The formula here given is substantially the one which has been hith- 
erto recommended by this Bureau, reduced to the45or50 gallon basis, 
or the capacity of the ordinary kerosene barrel commonly used in its 
preparation by the steam method. 
Unslaked lime pounds. . 20 
Flowers or flour of sulfur do 15 
Water to make gallons. . 45 to 50 
The flour of -ulfur. although requiring somewhat longer cooking, 
seems i<> make a- good a wash a- the tlowers of sulfur, but an hour of 
thoro cooking i- ample for either. Good quality -tone lime should be 
secured and slaked in a small quantity of hot water in the cooking 
vessel, say one-third the full dilution. The sulfur, previously mixt 
up into a -till paste, should be added at once to the slaking lime. The 
