354 GREENHOUSE MANAGEMENT. 



Evaporated sulphur is also a valuable insecticide foT 

 red spider, scale and aphides. 



Whale oil soap is a useful material for washing 

 plants, or as a solution for spraying plants that cannot 

 be readily washed, using one pound to eight or ten gal- 

 lons of water for tender plants, and a pound to three or 

 four gallons for the hardier ones. It is also much 

 used in making kerosene emulsion, being preferable to 

 common soap. 



There is also a great variety of patent mixtures that 

 are used as insect destroyers, among the most valuable 

 of which is Hughes's fir tree oil, which can often be used 

 to advantage upon plants that may be injured by the 

 kerosene emulsion. At the rate of a half pint to a gal- 

 lon of water, it is an effective and safe wash. 



TOBACCO EXTRACT. 



In large ranges of houses, where steam is used for 

 heating or pumping, the application of the vapor of 

 tobacco will be found easier, safer and more effective 

 than the use of smoke. It can readily be applied by 

 placing the stems in a barrel or tank and admitting 

 steam through a steam pipe to the bottom. Three bar- 

 rels will answer for a 100-foot house. Galvanized sheet 

 iron pans may be placed upon the steam pipes and used 

 for the evaporation of strong tobacco water. They are 

 generally about forty inches long, four inches wide and 

 nearly as deep, and if two are placed upon each side of a 

 house 100 feet long, and the pans filled twice a week, it 

 will generally keep the aphides in check. The commer- 

 cial tobacco extract can be evaporated in the same way, 

 but only a pint will be required for 4,000 square feet. 

 The extract may also be used as a paint upon hot water 

 pipes, applying it with a brush. It will soon dry on and 

 in a day or so should be moistened with clear water. 

 Another application of the extract should be made in a 

 day or two, as is necessary. 



