370 Elementary Principles of Agriculture 



minutes to thoroughly dissolve the sulfur. The sulfur dissolves 

 most easily in a thin, milky solution of lime, and, for this reason, 

 no more water is used in dissolving the sulfur than is necessary to 

 keep the mixture from becoming pasty. When the sulfur is thor- 

 oughly dissolved, pass the solution through a strainer and dilute to 

 the desired concentration with hot water. The mixture should be 

 prepared just as needed, and applied while still warm. 



8. Self-Boiled Lime-Sulfur Wash is a combination of lime 

 and sulfur boiled only with the heat of the slaking lime. It is 

 sometimes used for spraying peaches as a substitute for Bordeaux 

 mixture when the latter is injurious to the foliage. 



Sulfur, free from lumps 10 pounds 



Fresh lime 10 pounds 



Water 50 gallons 



Place the lime in a barrel, spread to keep the sulfur off the 

 bottom of the barrel and add about a gallon of water to start it to 

 slaking. Now add the sulfur and enough water to make the 

 mixture into a paste, about 3 to 4 gallons. Stir vigorously to 

 prevent caking at the bottom. After the violent boiling due to the 

 slaking lime is over, dilute freely to stop the boiling; strain to 

 remove the coarse particles of lime and add the full quantity of 

 water. 



9. Arsenical Insecticides. Formerly London Purple and 

 Paris Green were much used for insecticides. These substances 

 are heavy and are somewhat troublesome to keep mixed with the 

 water, and are likely to injure the foliage. In recent years arsenate 

 of lead has come into general use and has largely replaced other 

 arsenic compounds used for insecticides. It stays in suspension 

 longer and adheres better and is less likely to injure the foliage. 



Arsenate of lead 1 to 3 pounds 



Water (or Bordeaux or lime-sulfur) 50 gallons 



Arsenate of lead may be purchased in the form of dry powder 

 or as a putty-like paste. .As there are many grades of arsenate of 

 lead on the market some caution should be exercised in making 

 purchases. 



10. Kerosene Preparations. Kerosene oil is an external 

 irritant and is very effective in killing insects. It can not be applied 

 to plants, however, in its crude form, without producing serious 



