180 The Spraying of Plants. 



WHALE-OIL SOAP AND SULPHIDE OF POTASH WASH. The 

 following formulas for a summer wash have been recommended 

 by the Horticultural Commissioners of Sutter County, Cal. : 



" Whale-oil soap (80 per cent strength) 20 pounds. 



Sulphur 3 " 



Caustic soda (98 per cent strength) 1 pound. 



Commercial potash 1 " 



Water to make 100 gallons. 



" Place the sulphur, caustic soda, and potash together in about 

 2 gallons of water and boil for at least an hour, or until 

 thoroughly dissolved. Dissolve the soap in the water by boil- 

 ing ; mix the two and boil them for a short time ; use at 130 F. 

 in the vessel. 



" Professor Hilgard recommends, in bad cases of scale and in 

 fighting red spider, an addition of kerosene in the form of an 

 emulsion, to the above wash: 



" Kerosene . 1 gallon. 



Whale-oil soap \ pound. 



Water gallon. 



" Dissolve the soap in the water and when boiling hot add the 

 kerosene. Churn the mixture for five or ten minutes with a 

 hand spray-pump until it forms an emulsion. If the emulsion 

 is perfect it will be of a creamy nature, no oil appearing on the 

 surface. Add this to the 100 gallons of spraying material. 



"The sulphide of potash and the kerosene emulsion are often 

 made up in large quantities, and the proper amount is added to 

 the whale-oil soap as required. Keep this wash well stirred 

 when using. 



" It is very important that the whale-oil soap should be at 

 least 80 per cent strength. To test the soap, spread five or ten 

 ounces of it on a tin plate counterpoised on a pair of upright 

 scales reading to ounces, and then dry the whole by setting it 

 on top of a pot of boiling water. The loss in drying will indi- 

 cate the amount of water in the soap. Thus, if five ounces 

 were taken and one ounce was lost in drying, the soap would be 

 of 80 per cent strength." 



WHITE HELLEBORE. See HELLEBORE. 



YELLOW PRUSSIATE OF POTASH. See FERROCYANIDE OF 

 POTASSIUM. 



