72 Americaii Ilortieuliuval Society. 



means of diluting kerosene by emulsification with milk, shortly after our 

 publication of this method, repeatedly reoomnKMidcd a mixture of kerosene 

 made by stirring simjily, admitting, however, that 'if to be used very exten- 

 sively, the permanent emulsion might be more convenient.' 



"In Florida, where the original directions fcjr making a good emulsion 

 have been widely distributed, and whore the remedy itself is rapidly eoming 

 into universal use among truck farmers, as well as orange and fruit growers, 

 there is still need of greater care than is generally given to the preparation 

 of the wash. 



'• Failure in forming a stable emulsion is due, in most cases, to in.suflRcient 

 agitation of the mixture. The emulsion can be very quickly and easily 

 made by using a good force-pumji, so constructed that it can be inserted 

 directly into the liquid, which must be kept in constant and violent agita- 

 tion by forcing it through some form of spray-nozzle back into the same 

 receptacle. A pump otherwise good is less adapted to forming an emulsion 

 if, instead of being inserted directly into the i)ail, it has a large and long 

 supply tube, in passing through which the liquids are comparatively quies- 

 cent, and consequently have a tendency to separate. 



"Another frequent cause of failure is the attempt to form an emulsion by 

 churning together a small quantity of kerosene and a large quantity of dilu- 

 ent. Only a very unstable union can be effected by this means. The very 

 essence of the process requires that the oil shall be broken down by driving 

 into union with a smaller, or at most an equal, quantity of the emulsifying 

 solution, after which, if a genuine emulsion is formed, it may be diluted ad 

 libitum with water." 



These emulsions are most useful agents in the destruction of scale 

 insects, and have been especially valuable in the orange groves of Florida. 

 Care must be taken t<^ use petroleum only when properly emulsified; kero- 

 sene two gallons, common soap one-half jiound, water one gallon. A thor- 

 ough emulsification is necessary. When thorough there is an absence of 

 oiliness and it resembles thick cream. Failure in forming emulsion is 

 usually on account of insufficient agitation, also in using too small a quan- 

 tity of oil with a large quantity of diluent. There should be less of the 

 diluent than of o\\. 



After having obtained any good insecticide, its use is successful according 

 to the satisfactory character of the appliances. He called special attention 

 to the nozzles and other api)Iiancos planned and jierfected at the Depart- 

 ment of Agriculture, exhibiting samjjles and explaining their principles and 

 mode of use. This nozzle is easily cleaned and with difficulty fouled. He 

 considers it of great importance to success in applying insecticides, killing 

 the insects without injury to the i)lants. 



Apples. — Round-headed ai)i)le tree borer {Saperda Candida). Facts 

 brought to light by himself and Mr. Ilobson in 1878 are not generally un- 

 derstood. Most writers propagate the error of statement — the egg laid on 

 the bark. The egg is inserted in incisions made by female. In healthy 



