lo Aug., 191 



Tlic Olrrc. 



467 



s!iced-up hard soap, or 2 llis. of soft soap, until the soap is dissolved. 

 Remove from the fire and add 2 gallons of the oil, thoroughly agitate with 

 force syringe for about five minutes, or until emulsified, replace on the 

 fire again after adding the oil. The greatest care should be taken that it 

 does not boil over or drip into the fire, as, owing to its inflammat)le nature, 

 it is exceedingly dangerous. 



If the mixture has been properly prepared, it will set when cool, and 

 no free oil will be noticeable on top. The presence of free oil indicates 

 eitlier an insuffitnenry of soap or of emulsification. Sufficient stock may 

 he prepared at once in the abo\e way to last all through the season. In 

 making up for u.se the stock should be heated up or diluted in hot water. 



In applying the red oil preparation use at the rate of i in 20 to i in- 

 30, according to the time of application. In autumn or late summer, or 

 on badlv infested trees the stronger strengths may be used, while the 



FIG. 22.- -TERMINALS OF SHOOTS ATTACKED BY BLACK OLIVE SCALE. 



weaker solutions should be used in spring, when the new growth is on the 

 trees. The olive, being an evergreen tree, will not bear the winter 

 strengths used on deciduous trees. Crude petroleum and kerosene emulsion 

 should be used at strengths from 1 in 12 to 1 iii 15. 



Resin w'ash and the lime and sulphur wash may also be u.sed. Although 

 all the.se sprays are of value in reducing the pest, it is very rarely that 

 they succeed in completely eradicating it on evergreen trees. The only 

 •effective method of doing this economicalh is by fumigation with hydrocyanic 

 acid gas. Full particulars of this method appear in the Journal of Agri- 

 culture, June issue, 1912, pages 366 to 374 



The chemicals used and the gas generated are exceedinglv dangerous 

 poisons, and should be handled with the greatest care. The gas should 

 never be inhaled. The chemicals should be securelv locked awav when 

 not in use. 



