REPORT OF THE ENTOMOLOGIST. 559 



hole to a depth of about 6™™, and three additional plates of 2™° thickness had been 

 put on successively; a circular cavity formed in tlie chamber, and last the cap con- 

 taining the outlet fell off. This also liad been eaten nearly through. Not more than 

 1,000 gallons of wash had been sprayed with the nozzle. Tlxis may be largely due 

 to the impure and sandy water used. 



PREPARATION OF SOAP. 



At the beginning of my work, in preparing whale-oil soap, I used chiefly Babbitt's 

 potash or lye, which is sold in boxes of 4 dozen 1-pound cans, at from 9 to 10 cents 

 jier pound. To 1 pound of potash 2 gallons of water were added and placed over 

 lire. After all the potash had been dissolved, 2 pints of fish-oil were added and 

 contents cooked until the soap had formed; then 2 gallons more water were added 

 and well mixed together. This formed a soft soap, and would, after cooling, readily 

 mix with cold water. 



The cost of this soap is about | cent per pint, and 3 pints are required to 1 gal- 

 lon of water to destroy eggs and insects of Icerya. This would be 1 cent for 10 

 pints of wash. Fish-oil is sold generally at Los Aaigeles at about 32 cents per gallon, 

 wholesale price. 



Later, however, instead of using Babbitt's potash, I obtained caustic soda from 

 the Los Angeles Soap Company. This is sold at wholesale by the same firm at 

 5 cents per pound, and it is equally as good as Babl)itfc's potash. To 1 pound of 

 tliis caustic soda 3 pounds of gi-easo, or part of that and resin to the full amount, 

 should be taken, as will be shown in the experiments. Tliree pounds of tallow 

 and resin to 1 pound of soda did much better work than did 4 of the fii-st to 1 of 

 the last. Tallow is sold by the same fbrm at 3 cents per pound and resin at 1^ cents, 

 wholesale price. Almost any grease would answer in making soap, and much could 

 be saved for this purpose which otherwise would not be made use of. 



In making soap 152, 1 pound of caustic soda is dissolved in 1^ gallons of water; 

 then the 2 pounds of resin and 1 povmd of tallow is dissolved in 1 quart of the lye; 

 after the resin is all well dissolved by moderate heat the lye is added slowly, while 

 cooking, under continued stirring. The mixture, if good, wdll become dark brown 

 and thick. Should it become whitish and flocky (this is caused by too much and 

 too strong lye), water should be added and it will become right again. This will 

 make 22 pints of soap — for water should be added to make that amount after all the 

 lye is in — at a cost of 11 cents, excluding fuel and labor m preparing it, wliich 

 amount to but httle, and will be sufficient for 44 gallons of wash if sprayed weU. 

 This is for Icerya.. I would not recommend it stronger than ^ cent for a gallon of 

 the wash. 



The same rule is to be observed in preparing soap No. 144. This has been ti-ied 

 also on two large trees by Messrs. Wolfskill and Craw, at J cent per gallon of the 

 wash. All eggs and insects were destroyed and the tree left in excellent condition. 



In preparing these soaps the resin and tallow should never be dissolved without 

 the additional lye. It will become so hot, that if a little lye is added a good part 

 of the contents of the kettle wUl boil over. All this is avoided by adding the lye as 

 said above, and the resin will dissolve the quicker. 



In making tallow soap for experiment 77 the caustic soda should be dissolved in 

 somewhat less water. One gallon is used. After the tallow and resin are dissolved 

 together (in this soap it can be done without the lye) the lye should be added slowly 

 while boiling, and afterward the required water added, ^liirty-seven joints of soap 

 were made in experiment 77 at i cent per pint. In using caiistic soda the cost of 

 same quantity — i. e., 1 pound of soda, 5 cents: taUow, 2^ pounds, 7.5 cents; reshi, i 

 pound, 0.73 cent — would be only 13^ cents; and in making 40 pints of soap this would 

 be i cent per pint. One pint of soap to 7 pints of water would be sufficiently strong 

 to kill the scales and their eggs. 



A soap emulsion prepared cold is used extensively in and around Los Angeles. I 

 . have not seen any good results from it. If mixed with water free oil would float on 

 the top, and trees treated with it would lose half their leaves and be arrested iii 

 growth for weeks. The fruit would be burned and marked from the excessive caus- 

 tic it contains. I have seen several hundred trees in such condition in the Wolfskill 

 orchard. The consistency of this particular mixture I coiild not learn. Never, and 

 I have been assured so by experienced soap-men, can a proper soap be made except 

 by cooking. Although my experiments 35 and 71 show good results, I would not 

 recommend them. 



RESIN COMPOUNDS. 



These I found excellent for destroying Icerya. and the few experiments made on 

 the Red Scale {AspicUotus aurantii) showed promising results; yet fui'ther experi- 



