INSECTS AND INSECTICIDES 
35 
they have considerable insecticidal value, particularly for the de- 
struction of very tender insects, like plant lice. The scans that 
are specially useful for the destruction of insects, are sold as^hale- 
isZXihoi r p ’ or tree - soaps - whatever the name - 
12. WHAEE-OIE OR TREE-SOAP. 
For ordinary plant lice one pound of the soap to eight or ten 
t g his°strenl 7 h ter ii S Sll ,* C - ent if the a PP licatio » is thorough. Double 
this strength will not injure most plants and is often required to 
destroy more resistent insects. For scale lice, like the San Jose 
scale for example, it is used as strong as a pound, or even two 
pounds, to a gallon of water. These strongest applications can 
mint 111 the wlnter _ or earl y s P rin g wh en the trees are dor- 
ant. The soap is more effectual if applied when quite hot. 
13. FISH-OIE SOAP (home-made). 
Lodeman in his “Spraying of Plants” gives the following for¬ 
mula for the preparation of fish-oil soap: 
Potash lye. 1 
Fish-oil ...." ,.. 1 P9 u nd 
Soft water. .a “ P lnts 
Dissolve the lye in boiling water and then add the oil and boil 
Tirs longer When using dissolve a pound of this soap 
m from six to ten gallons of water. Use for the same purposes as 
whale-oil soap, and m the same strengths. 1 1 
14 KEROSENE EMUESION. 
cide for tbe r H Pa f rati 7 n iS ? r ° bably , the best g ener al purpose insecti- 
e for the destruction of insects by external contact. The mate¬ 
rials composing it are always at hand and it is not difficult to 
beTsed ff t6r ° n Ki haS rf? a f ttle ex P erie nce. Soft water should 
“break”’ t firsS A* & T** is ., used k may be necessary to 
break it first by adding washing soda or potash lye. 
To make the emulsion use the ingredients in the following 
proportions: & 
Kerosene...o 1 P ?i Unc ^ 
Water. .^ a 11 0ns 
^^P are by dfssolvmg the soap in a gallon of water, then 
while the soapy water is boiling hot, remove from the fire and 
mmediately add two gallons of kerosene and agitate briskly for a 
few minutes. If a large amount is being made, use a force pump- 
and forcibly pump the mixture back into the receptacle that com 
