256 STATE BOARD OF HORTICULTURE. 



(2) Rosin Solution. 



(For newly hatched Black Scale and Soft Brown Scale.) 



Rosin 18 pounds. 



Caustic soda (70 per cent) 5 pounds. 



Fish oil 2\i pints. 



Water, to make 100 gallons. 



Prepare as directed in formula No. 1. The black scale 

 generally completes hatching in most sections by September 

 1st, therefore this formula should be used during that month. 



(3) Kerosene Emulsion. 



(For Black Scale and Soft Brown Scale on citrus trees.) 



Kerosene oil (Pearl, 150° test) 5 gallons. 



Common laundry soap 11+ pounds. 



Water 2\:, gallons. 



Dissolve the soap by boiling in 2-i^ gallons of water, and 

 while boiling remove to another vessel; add the kerosene, and 

 churn for fifteen minutes, or until a perfect emulsion is formed. 

 Afterward dilute with 6^ gallons of hot water for each gallon 

 of oil, and to the mixture add 2^ pounds of home-made soap 

 dissolved in hot water. Apply at a temperature of 140° F. 



(4) The Hydrocyanic Acid Gas Treatment. 



(For destroying scale insects on citrus trees.) 



This treatment should be used in the night to avoid light, 

 heat, and sea breeze, which neutralize the effects of the gas. 

 The chemicals used for producing the gas are: Sulphuric acid 

 (commercial), cyanide of potassium (98 to 99 per cent), and 

 water. 



The following instructions must be carefully observed: First, 

 the tent, which must be air-tight, is placed over the tree; 

 second, the tent is made air-tight around the bottom, by throw- 

 ing some loose soil over the bottom of the canvas; third, the 

 necessary amount of sulphuric acid, together with the required 

 amount of water, is put in a glazed earthenware vessel, and 

 placed under the canvas, and the cyanide of potassium is 

 added. A piece of sacking or burlap is thrown over the top of 

 the vessel, to spread the gas and prevent it from burning the 

 leaves immediately above the generator. The tree is left 

 covered forty minutes. 



