OBSERVATIONS, CORVALLIS, OREG. 25 



ing, then, an opinion upon thin single set of experiments, it would 

 appear: 



(1) That when lime is not used a Paris Green containing 4 per cent 

 of soluble arsenious oxid can be used on apple trees, while one con- 

 taining 7 per cent can be used with the addition of lime. 



(2) That if lime is not used a Paris Green containing 4 per cent of 

 soluble arsenious oxid can be used on plum trees. If lime is used it 

 would appear that a Paris Green containing 5 or 6 per cent might be 

 safely used. 



REPORT FROM THE OREGON STATION, CORVALLIS. 



By C. B. CORDLEY. 



In the experimental work done in testing the effects of .varying 

 amounts of free arsenious oxid in Paris Green on foliage, the direc- 

 tions were very carefully followed. For each test the required amount 

 of water was placed in a barrel, to which was added the amount of milk 

 of lime specified, if any, and then the Paris Green. The whole was 

 stirred thoroughly and at once sprayed upon the trees. The work was 

 done with a small hand pump, fitted with a Vermorel nozzle, and great 

 care was exercised to see that every leaf was thoroughly sprayed. In 

 addition to the work outlined the effect of the stronger sprays (1 ounce 

 to 9.5 gallons) on the foliage of a few delicate plants was tested. 



The sprays without the addition of lime were applied on July 10, 

 1903. Evaporation was so rapid that the foliage was dry a few 

 moments after being sprayed. On July 11 the conditions were similar, 

 and samples Nos. 1 to 3, with 15.5 gallons of water and 2 ounces of 

 lime, were applied. The remainder of the samples of that set, Nos. 

 4 to 6, with 15.5 gallons of water and 2 ounces of lime, and Nos. 1 to 6, 

 with 9.5 gallons of water and 2 ounces of lime, were applied on July 17. 



In the meantime, i. e., from July 10 to July 17, the weather had 

 remained clear and bright. A critical examination, made on the latter 

 date, of the trees sprayed on July 10 and 11 showed that none of them 

 was injured. 



On Juty 21 and 23 there were slight showers, and cloudy weather 

 continued throughout the week. Thorough examinations were made 

 on July 23, August 3, and December 1, the results of which are given 

 in the tabular statements which follow. A table is also given show- 

 ing the meteorological conditions which obtained for a number of 

 days following the application of the sprays. 



