1 66 



THE CANADIAN HORTICULTURIST. 



liortlcaiix and Paris green (K-L-B-P) and 

 resin soap. 



During the past month a considerable 

 amount of work on this and alHed forms of 

 emiulsion 'has 'been done in the laiboratories 

 of the Experimental Farm, Ottawa, and 

 fthough this research is not completed, it may 

 be advisable, as we are now at the season 

 when spraying must 'be more particularly at- 

 tended to, to publish certain of the more im- 

 portant facts which the work has brought to 

 light. 



First : Fres'hly slaked lime makes a 

 smoother emulsion and one that stays in sus- 

 pension longer than one made with ordinary 

 air-slaked lime; the latter, however, fur- 

 nishes a satisfactory emulsion if it is not too 

 much carbonated by long exposure to the 

 air. 



Second : By using lime slaked imme- 

 diately 'before using, the quantity may be 

 niater'ia'llly ireduced. A perfect eniiulsion 

 can be made by slaking half pound of good 

 quicklime and emulsifying with one quart 

 of kerosene and two gallons of water. 



Third : By the use of freshly slaked lime 

 less time is needed for the churning in order 

 to 'bring the mass to a perfect emulsion. 

 Much, of course, depends on the vigor used 

 in this part of the preparation, but on small 

 quantities two to three minutes of continu- 

 ous pumping were found sufficient. 



Fourth : It is not apparently a matter of 

 nnuch moment that the lime be dry and pow- 

 dery when mixed with the kerosene. Ex- 

 cellent emulsions have been made both from 

 air-slaked lime and freshly slaked lime when 

 they have been quite moist or even mvade 

 into a thick cream with water before a.d'ding 

 the kerosene. 



FivOUR EMUIvSION. 



Fifth : Flour has been successfuHv sub- 

 stituted for lime. Beginning with the same 

 weight as proposed by Prof. Close, viz., one 

 pound to one quart of kerosene, which made 

 a perfect emulsion, the amount of flour has 



stq) by step been reduced until it was found 

 that eight ounces were sufficient to hold in 

 perfect suspension the quart of kerosene. 

 The preparation with flour is most simple. 

 The requisite amount of kerosene is placed 

 dn the vessel (pail or 'barrel) — which is prc- 

 -ferably dry — and flour added in the propor- 

 tion stated, viz., eight ounces to one quart, 

 the who'le thoroughly stirred and the water 

 added, two gallons for every quart of kero- 

 sene. This is then vigorously churned as 

 already described. The time necessary to 

 churn will vary from two to four minutes, 

 according to the quantity to be emulsified, 

 and the emulsion is then ready for use. 



When the emulsion is required for imme- 

 diate use, the quantity of flour may be fur- 

 ther reduced. It was found that as small 

 a quantity as two ounces would emulsify 

 one quart of kerosene, but that on standing 

 a few hours a perceptible layer of kerosene 

 had separated. 



It has, further, been found that by -scald- 

 ing the flour before adding the kerosene a 

 less weight is required. An excellent emul- 

 sion, which showed not the slightest separa- 

 tion of kerosene after one week, was pre- 

 pared by scalding two ounces of flour, mix- 

 ing the resulting paste with one quart of 

 kerosene and emulsifying with two gallons 

 of water. 



The flour emulsion is smooth, readily and 

 easily atomized, and does not clog the nozzle. 

 Any separation into layers (no free kero- 

 sene will appear for several days, at least) 

 may be readily overcome or remedied by 

 simply stirring the mixture. It is equally 

 effective, as might be expected, as an insecti- 

 cide with the lime-formed emulsion, and 

 amongst other advantages that may be 

 claimed for it there is no perceptible whiten- 

 ing of the tree or foliage ; and, further, in 

 some places it may be found cheaper and 

 easier to make than the lime emulsion. Its 

 use is suggested as an alternative where 

 good lime is unobtainable and also for mak- 



