THE COTTONY-CUSHION SCALE. 41 



In America they have well nigh exhausted the whole 

 pharmacopoeia of remedies, including the gas treatment, 

 as explained in Part I. of this book. We have, however, 

 a cheap and effective remedy in a timely application of 

 kerosene emulsion, sprayed on whilst hot, 160 Fahr. ; 

 and this, if properly done, no cottony-cushion scale can, 

 for any length of time, withstand. 



In former times, the complaints have been that the 

 material used cools before it reached the tree, but with 

 the alterations that I have suggested, and of which an 

 engraving is here given, it is hoped that these objections 

 will have been permanently overcome. When an isolated 

 tree is very badly affected, if it be not too valuable 

 a one, grub it out at once and burn it on the spot. 

 If it be a valuable plant, thin out as much wood 

 as possible, burning same as before. Now get your 

 spraying machine ready, light up, and when heated to, 

 say, 150 or 160 spray the tree thoroughly, being 

 careful that no portion of the tree or plant is missed. 

 Do not wait until the plant begins to send forth its 

 tender shoots, as in this 1 stage the very hot mixture 

 may scald the foliage, which in this stage is very 

 easily affected. If the foliage remains unhurt after 

 the first spraying, give another dressing in about a 

 week's time, and the mixture in both cases may be 

 used at about one part of emulsion to fifteen of 

 water. 



There is a great deal to be considered in making a 

 good emulsion, otherwise the materials are sure to sepa- 

 rate, in which case you simply use pure kerosene and 

 pure water separately, and the wonder then is why the 

 trees are damaged. This hot mixture should not be used 

 on tender shoots. 



In making an emulsion, use the mineral soap. I have 

 tried this for spraying myself and find it to answer 

 admirably, and in this case the emulsion when once 

 made cannot separate, nor will it, so far as I have ascer- 

 tained, injure the foliage of the most tender tree. The 

 emulsion is so perfect that the material adheres to the 



