SCIENCE OF FRUIT-SPRAYING 339 



operate against them, but if a specific wash is wanted it 

 may be found in the following : 



i gallon of paraffin. 

 5 Ibs. of soft soap. 

 25 gallons of water. 



To facilitate mixing first boil the soft soap in a gallon 

 of water, add the paraffin directly the soap is taken off 

 the fire, stir the mixture, pour it into a tub with the full 

 quantity of water and churn up well with a syringe. The 

 scales fasten on the bark of Apple and Pear trees, and 

 the trunks must be well wetted. 



Mildew of Strawberries is best dealt with by spraying 

 the plants at the first sign of an attack with sulphide of 

 potassium, i oz. to 2j gallons of water. 



Side by side with the advance in the use of sprays has 

 gone improvement in appliances. The engineer has 

 watched the experiments of the chemist with close 

 attention, and supplemented them with improved 

 sprayers. 



In large cultures horse sprayers have been developed, 

 and for smaller cultures knapsack sprayers. In both the 

 liquid is spread by means of a force-pump through 

 nozzles specially devised to facilitate cleaning if they 

 should become clogged. The liquid is blown out in a 

 mist-like state, and this is essential to economical dis- 

 tribution, because if it was spread in a coarse spray most 

 of the liquid would run off. 



Modern forms of sprayer are operated by compressed 

 air. The vessel is first charged with the prescribed 

 quantity of a suitable fungicide or insecticide, and then 

 air is pumped in beneath the liquid. When the proper 

 pressure has been obtained a tap is turned and the 

 liquid is forced out in a fine spray until the vessel is 

 completely emptied, These sprayers dispense with the 



