14 



on two or three of the trees, and the others show a loss of from 15 to 50 per cent. I 

 argue that as the trees first sprayed show a lesser loss than the others, the probabili- 

 ties are that the water and compound were not thoroughly mixed, and as it is my cus- 

 tom to keep the inlet pipe of the pump near the top of the solution to avoid the sedi- 

 ment, these trees received a weaker solution, as the compound would remain at the 

 bottom of the tank until thoroughly mixed and suspended in the water. No condi- 

 tions of health of trees or soil affected the loss of foliage, since similar results are 

 shown by the trees in the other part of the grove. My conclusion is that the cause 

 exists in too strong a solution, followed by hot, dry winds for several days. Since 

 the date of spraying there has been no rain nor even a fog or cloud until two days 

 ago. I am happy to say, though, that the bugs are dead. 



That this disastrous result to the foliage was the direct effect of the 

 hot drying wind appears to admit of no doubt, since Mr. Ryan informs 

 me that when no such wind prevailed he had sprayed a large number of 

 his orange trees with a compound made precisely like the one used 

 above, and the trees thus sprayed dropped scarcely a leaf. The fact 

 that the latest trees sprayed suffered the most indicates not so much 

 that they were sprayed with a stronger solution than the others, but 

 rather that being sprayed later and being still wet with the solution 

 they would naturally be more affected by the hot winds than those 

 which were sprayed earlier, and from which the surplus solution had 

 had time to drip off, while the remainder would be quite dry before the 

 hot wind occurred. 



Following is an account of a number of experiments which I made 

 with various resin compounds and resin soaps for the destruction of the 

 Red Scale (Aspidiotus aurantii Maskell) ; they were made at Orange, in 

 the adjoining county of Orange, upon trees kindly placed at my disposal 

 by Mr. H. F. Gardner. The trees in experiments 1S1-194 contained no 

 fruit, but there were green oranges on all of the other trees experi- 

 mented upon. 



In making each of these solutions the necessary ingredients were 

 placed in the boiler, covered with water, and boiled briskly from two to 

 three hours, after which they assimilated well with water ; the solution 

 was then diluted with the proper quantity of water, strained through a 

 piece of barley sack, and then sprayed upon the tree. In each instance 

 only a small quantity of solid or semi-solid matter was strained out of 

 the different solutions. An exception to this occurs in experiments 185 

 and 186, in which the resin was simply dissolved in water over a hot 

 fire, after which the necessary quantity of water was added and the 

 solution strained, as described above. In dissolving the resin I used 

 3 gallons of water for each pound of the resin ; at first I tried to dissolve 

 it at the rate of 1 pound of resin to 2 gallons of water, but a portion of 

 the resin would not dissolve until more water had been added. The 

 solution was of a milky-white color, and assimilated well with water. 



The cost per 100 gallons of the different preparations as given below 

 is based upon wholesale prices of the different ingredients, furnished 

 me by the Los Angeles Soap Company, of this city. The rate on resin 

 is by the 10-barrel lot of 375 pounds per barrel ; of caustic soda, by the 



