294 INSECTICIDAL MATERIALS AND PRACTICES 



Distillate emuhion. — 5 gallons of 28° grax'ity untreated distillate ; 

 5 gallons boiling water, \\ pounds whale-oil soap. Dissolve the 

 soap in hot water, add the distillate, and thoroughly emulsify by 

 means of a power pump until a yellowish, creamy emulsion is 

 produced. For use on lemon dilute with 12 parts of water; 

 on orange, with 15 parts. 



Formerly much used on citrus trees, but now generall}' replaced 

 by fumigation. 



Hellebore. — See White Hellebore, p. 300. 



Hot water. — Submerge affected plants or branches in water at a 

 temperature of about 125°. For aphis. It will also kill rose-bugs 

 at a temperature of 125°-135°. 



Kerosene emulsion. — Hard, soft, or whale-oil soap, i pound ; water, 

 1 gallon ; kerosene, 2 gallons. Dissolve the soap in hot water ; 

 remove from the fire and while still hot add the kerosene. Pump 

 the liquid back into itself for five or ten minutes, or until it 

 becomes a creamy mass. If properly made, the oil will not sep- 

 arate out on cooling. 



For use on dormant trees, dilute with from 5 to 7 parts of water. 

 For killing plant-lice on foliage dilute with from 10 to 15 parts of 

 water. Crude oil emulsion is made in the same way by substitut- 

 ing crude oil in place of kerosene. The strength of oil emulsions is 

 frequently indicated by the percentage of oil in the diluted liquid: — 

 For a 10 per cent emulsion add 17 gallons of water to 3 gallons 

 stock emulsion. 



For a 15 per cent emulsion add lOj gallons of water to 3 gallons 

 stock emulsion. 



For a 20 per cent emulsion add 7 gallons of water to 3 gallons 

 stock emulsion. 



For a 25 per cent emulsion add 5 gallons of water to 3 gallons 

 stock emulsion. 



Lead, arsenate of. — See under Arsenical.s, ]). 291. 



Lime-suljur. — A compound of lime and sulfur makes both a good insec- 

 ticide and a good fungicide (for an account from the fungicide point 

 of view, see page 256). There are several forms of it, as (1) the 

 ordinary dilute home-made ; (2) the concentrated home-made ; 

 (3) the commercial concentrated brands ; (4) the so-called self- 

 boiled preparation. The three first are solutions, and are modi- 



