162 The Spraying of Plants. 



soda, of 76 per cent ; or 1^ pounds of solid caustic soda, of 63 

 per cent. This is used in the same way and for the same pur- 

 pose as No. 1. 



OREGON WASH. The Oregon wash is practically the same 

 as the California lime, salt, and sulphur wash, with the excep- 

 tion that sulphate of copper is substituted for salt. The for- 

 mula, as given by Henry E. Dosch, of the Oregon State 

 Board of Horticulture, is as follows : 



"Place 100 pounds of sulphur and 80 pounds of lime in a 

 boiler with 100 gallons of water, and boil slowly until the 

 sulphur is dissolved. Dissolve 8 pounds of sulphate of copper 

 in hot water, add to 20 pounds of slaked lime, and mix the 

 whole together. When ready to spray, take 1 pound of the 

 mixture and 2 gallons of hot water, for winter use, applying 

 lukewarm ; 1 pound of the mixture to 8 or 10 gallons of water 

 for summer spray. The water in the mixture will boil away, 

 leaving a solid mass, which, however, dissolves readily when 

 hot water is added for spraying." 



PARAFFINE. See KEROSENE. 



PARIS GREEN. See page 121. 



PATENT INSECTICIDES. The Division of Entomology of the 

 United States Department of Agriculture made an exhibit at 

 the Columbian Exposition, in 1893, of forty-two different 

 patented insecticides; and many more exist. Some possess 

 value, while others are positively unsafe to handle. As a rule, 

 it is better and cheaper for each grower to prepare the insecti- 

 cides and also the fungicides which are to be applied, since then 

 there can be no doubt as to their composition. 



PERSIAN INSECT POWDER. See PYRETHRUM. 



PRECIPITATED CARBONATE OF COPPER. See COPPER CAR- 

 BONATE. 



PODECHARD'S POWDER. 



Copper sulphate 45 pounds. 



Water, enough to dissolve. 



Lime, air-slaked 225 " 



Ashes 30 " 



Flowers of sulphur 20 " 



The copper sulphate solution should be poured upon the lime, 

 which in turn must be surrounded by the ashes to keep the 



