ACTION OF LEAD ARSENATE ON FOLIAGE. 49 



that the arsenic had gone into solution in very considerable quan- 

 tities. A parallel experiment was carried out with salt, in which 

 only 1 gram of salt was used to the 2,000 grams of water. This was 

 inot allowed to stand quite three days when 1,500 grams were filtered 

 ioff, concentrated and tested for arsenic. This concentrated solu- 

 tion was found to be so heavily charged with arsenic that only a 

 Ismail part of it gave an unmanageable amount of arsenic when 

 brought into an active Marsh apparatus." 



Still more exhaustive experiments than those here reported are 

 being made in the orchard this year, which it is hoped will definitely 

 settle this point. It was deemed best to report the progress that has 

 been made before waiting for the final conclusions or for the results 

 of other experiments along the same line, some of which have sug- 

 gested themselves since this work was begun. The full data obtained 

 from the 1909 experiments have not as yet been collated, but some 

 interesting results have been obtained and may be briefly mentioned. 

 Load arsenate was applied to peach trees in the same proportions 

 as in previous experiments that is, 1J pounds (dry basis) to 50 

 gallons and three applications were made. 



(1) When applied with spring water (analysis of which has been 

 given), some injury to foilage resulted, but it was not nearly so 

 marked as in the preceding year, and a longer time elapsed before 

 the injury was noticeable. 



(2) When applied with distilled water very slight injury occurred, 

 noticeably less than when the spring water was used. 



(3) When applied with distilled water to which 10 grains per gal- 

 lon of sodium chlorid had been added, rather serious injury resulted. 

 When, distilled water containing 40 grains of sodium chlorid per gal- 

 lon was used, the injury was very much increased, practically 50 per 

 cent of the foliage being affected. 



(4) When applied with distilled water containing 10 grains of 

 sodium carbonate per gallon, injury was noticeable fourteen days 

 after the first application, and seven days after the third application 

 the trees were almost completely defoliated. 



(5) Applied with distilled water containing 10 and 40 grains of 

 sodium sulphate per gallon, some injury resulted, but this was not 

 so marked as that produced in the presence of sodium chlorid. 



In similar experiments where lime was added at the rate of 4 

 pounds to 50 gallons, injury to the foliage was almost entirely pre- 

 vented. 



