352 GREENHOUSE MANAGEMENT. 



Another class of insecticides, in order to be effectual, 

 should be applied directly upon the insects, as they 

 destroy by contact, and their effect is not lasting. 



KEROSENE EMULSION. 



Another remedy that is coming rapidly into favor 

 for the destruction of aphides, scale, mealy bugs, and all 

 other insects to which it can be directly applied, is 

 known as kerosene emulsion. Various pumps and noz- 

 zles have been designed for the mixing of water with 

 kerosene, but as yet the emulsion is safest to be used. 

 It is prepared with either hard or soft soap, kerosene 

 and water, as follows: Take a quart of soft soap that has 

 been heated until it has become liquid (or two ounces 

 of hard soap dissolved in a gallon of hot water), add one 

 pint of kerosene and mix together until a thick, cream- 

 like material is obtained. It can be best prepared by 

 using a small force pump, such as is used in applying 

 the mixture to the plants. Care should be taken to 

 form a perfect emulsion that will not separate upon 

 standing. Before using, the emulsion should be diluted 

 with water, so that the kerosene will constitute one-six- 

 teenth of the entire mixture, or, in other words, one 

 pint of kerosene will make eight quarts of insecticide. 

 This should be applied with considerable force and in a 

 fine spray, covering every part of the plants, as it must 

 come in contact with the insects, to be effectual. When 

 properly prepared, this mixture can be used with safety 

 upon nearly all plants. The cucumber and similar 

 plants, and a few others with rough leaves, will, how- 

 ever, be injured by it. For the more tender plants, 

 Professor "Webster recommends one ounce of hard soap 

 dissolved in two gallons of hot water, and mixing with it 

 one ounce each of oil of cloves and kerosene. In this, 

 while at a temperature of 125 degrees F., the plants 

 are drpped. 



