160 The Spraying of Plants. 



When the soap is dissolved, unite solutions (a) and (6), and 

 boil for a short time. The remedy is particularly valuable in 

 treating scale insects just as they hatch in spring. It is more 

 effective if used warm, at a temperature of 130 F., taking care 

 to reach as many insects as possible. 



MERCURIC CHLORIDE; CORROSIVE SUBLIMATE; HoCL 2 . 

 It is made by subliming a mixture of mercuric sulphate and 

 common salt, the resulting product being one of the deadliest 

 poisons. Recommendations for its use as an insecticide are 

 occasionally advanced, but the poison has such a caustic action 

 upon foliage, that it cannot be used with safety. 



It possesses some value as a fungicide, however, especially in 

 preventing scab upon potatoes. For this purpose use : 



Corrosive sublimate 2 ounces. 



Water 16 gallons. 



Scabby seed potatoes should be soaked in this solution for 

 about an hour and a half before planting. 

 MERCURIC CHLORIDE WASH. 



Corrosive sublimate 1 ounce. 



Soft soap 10 gallons. 



Alcohol or wood spirit 1 pint. 



Water, sufficient to make a stiff paint. 



The corrosive sublimate should first be dissolved in the alco- 

 hol, and this solution then added to the soap. The wash is 

 used upon the bases of apple trees to prevent the entrance of 

 borers, and for this purpose it has been highly recommended. 



MIXTURE No. 5 (of the U. S. Department of Agriculture). 



Ammoniated copper sulphate 1 part. 



Ammonium carbonate 1 " 



Twelve ounces of the mixture should be dissolved in 22 

 gallons of water, when it is ready for immediate use. A more 

 concentrated solution, consisting of 1 pound to 25 gallons of 

 water, has also been recommended. The fungicide has not 

 been generally adopted, as it frequently causes injury to foliage. 

 Before being dissolved, the mixture should be kept in air-tight 

 receptacles, or its composition will change. 



MODIFIED EAU CELESTE. This well-known fungicide is one 

 of the best now in use. In composition it is practically the 



