61 



mixed, and strained into the spraying machine. Lees advises 

 that the lime should be allowed to slake for from 6 to 12 hours, 

 before it is used. 



If a lime-sulphur wash is required instead of plain lime 

 wash it is suggested that the concentrated solution should be 

 obtained from the manufacturers, unless it is to be used on a 

 large scale, when it may prove economical to make it locally. 



II. Nicotine Wash. 



Nicotine, 98 per cent f-1 oz: 



Soft soap ... ^-1 lb. 



Water 10 gal. 



The nicotine and soap are dissolved in the water. The 

 soap may be first mixed with a little hot water in order to 

 dissolve it more quickly. If the 'water used is at all " hard 

 1 lb. of soap will probably be needed to every 10 gallons of 

 the wash ; with rain water J- lb. will be sufficient. 



Ill . Paraffin Emulsion.* 



Paraffin 1 pint. 



Soft Soap. ... 1 lb. 



Liver of sulphur (if needed) ..: 2 oz. 



Water ..: 10 gal. 



The soap should be dissolved in about 1 gallon of boiling 

 water and the paraffin added while the liquid is still hot. 

 The mixture should be thoroughly churned, preferably by 

 spraying it back into itself with a hand syringe. The 

 remainder of the water, in which, if necessary, the liver -of 

 sulphur is dissolved, should then be added, and after it has 

 once more been thoroughly churned the fluid is ready for use. 

 Unless the mixture is completely emulsified the paraffin is 

 liable to burn delicate foliage, and it should, therefore, be 

 prepared and used with care. It has, however, the very 

 marked advantage that the necessary ingredients are always 

 easily obtainable. 



Formuke for making other " contact insecticides," such us 

 resin wash or quassia, may be obtained on application to the 

 Ministry. In certain circumstances it is convenient to use 

 a proprietary contact insecticide to avoid the trouble of pre- 

 paring the home-made washes. 



* Lees (Annual Keport of the Long Ashton Kesearch Station, 1913, 

 p. 71) suggests this formula", but without the liver of sulphur. 



