THE SAN JOSE SCALE 301 



rinced that tlie choice lies between the expense of the wash and the 

 toss of the trees. 



The above are known as " winter washes," since they may only 

 be used without serious injury to the tree during its winter dor- 

 mancy. Later, it would not be safe to apply them unless in a con- 

 siderably diluted form, when they would only suffice to destroy a 

 portion of the scales. 



Some-made whale-oil soap. — For those who would prefer mak- 

 ing the soap for themselves, at a less cost than if purchased by the 

 small quantity in market, Mr. Howard has given the following 

 formula : — Potash lye, one pound ; fish oil, three pints ; soft water, 

 two gallons ; dissolve the lye in water and add the oil on bringing 

 the mixture to a boil ; boil for about two hours and then add suffi- 

 cient water to make up for the evaporation. This will make about 

 twenty pounds of soft soap — equivalent to about five pounds of th« 

 hard. 



The winter resin wash. — The composition and proportions given 

 for this, are as follows: — Resin, 120 pounds; caustic soda, 30 

 pounds ; fish oil, 15 pints ; water sufficient to make 100 gallons. 

 The resin and soda are broken up and, together with the fish oil are 

 placed in a large kettle, sufficient water being added to cover them. 

 The whole is then boiled for several hours, or " until the compound 

 will mix properly in water without breaking up into yellowish 

 flakes." {Insect Life, vii, p. 293). 



Potash wash. — Dr. Smith, in his experiments with the scale in 

 New Jersey, has tested to his entire satisfaction the efficacy of a 

 saturated solution of crude or commercial potash, i. e., potash in a 

 sufficient quantity of water to dissolve it, to be used upon trees dur- 

 ing their dormancy in the winter season, only. It may be applied 

 either by means of a cloth or stiff brush, or by thorough spray- 

 ing. The potash eats into or corrodes the scales and kills a large 

 proportion of the insects beneath them. A month later, by which 

 time the scales will have become riddled or loosened, it should be 

 followed with kerosene emulsion made after the usual formula and 

 diluted to a strength of one part to five parts of water. If these 

 applications are thoroughly made, — according to Dr. Smith, " not a 

 single insect need escape." 



Before using any of the above washes, it is recommended to cut 



