INSECTICIDES. 59 



Whale oil and hard white laundry soap has been 

 recommended for use in the preparation of this insec- 

 ticide ; but as soft soap finds greatest favour among 

 English horticulturists, I see no valid reason why it 

 should not be used. It mixes thoroughly well with 

 paraffin, and does not solidify. 



Smith's " Swift and Sure."- -This is a very effective 

 insecticide for soft-bodied and unprotected " scale " 

 and "mealybug," but its effect upon the small shield- 

 covered scales (Diaspinse) is of very little service. 

 For hard-wooded plants without leaves it has been 

 found most effectual when applied at a temperature of 

 from 130 to 140 F., and for plants with leaves heated 

 to not more than 100 F. 



" Fir-tree Oil." An old and well-tried remedy ; but, 

 like paraffin, is apt to " scorch " or burn the foliage if 

 applied in bright sunlight. If applied to foliage, the 

 plants should receive a good syringing the day after its 

 application. But this need not be done when the appli- 

 cation has been made on plants or trees without leaves. 



Soft Soap. For " sponging " greenhouse plants this 

 is a most efficacious remedy. For this purpose it is 

 used in varying strengths of from 1 to 3 oz. per gallon 

 of water ; the weaker solution should be used for such 

 tender plants as Eucharis, etc. For bark application 

 only it may be used at a strength of 8 oz. to the gallon 

 of water. For " mussel scale " infesting the trunk and 

 main branches of apple and pear, as also for Crypto - 

 coccus fagi infesting beech trunks it has proved a com- 

 plete success. In all cases it is best to dissolve the soap 

 by boiling it in a quart of water, afterwards adding the 

 full quantity. 



" Gislmrsfs Compound."- -This is an excellent com- 

 pound, and for " sponging " plants I have never found it 

 excelled. I have also found it the best remedy for 

 " buggy " vines. But, like other patent insecticides, it 

 is much too costly to use on a large scale. 



Lime Wash, or Lime Water. This should be made 

 of good fresh lime. I have twice seen this applied to 



