34 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 3 



question of absorption of arsenic by the roots with the nutrient solu- 

 tions. We have some cases of trees decidedly small for their age ; the 

 bark has an unhealthy color, the foliage is small. The trees make very 

 little growth and yield fruit of medium size but of very high color. 

 We find some trees in these orchards with corroded crowns, but the 

 trees to which I now allude are not affected in this way. Some of 

 these trees have died, the heart wood was found to be stained, the bark 

 was yellow and cracked and the woody tissue was rich in arsenic. The 

 general condition of the orchards is one indicating malnutrition. 

 Neither a lack nor an excess of water can be appealed to as factors in 

 these cases, for the land is in all cases that I have in mind high and 

 the supply of irrigation water abundant. There is, further, no defi- 

 ciency of plant food in the soil, provided the results of a chemical 

 analysis have any value whatsoever. All of the orchards in which I 

 have found these conditions obtaining are well cared for, and the 

 condition cannot be attributed to neglect. These trees often show 

 bleeding from wounds made in trimming, also from longitudinal 

 cracks in the bark. The material which collects on these wounds or 

 flows from the cracks in the bark is rich in lime, 25 per cent calcium 

 oxid, and also in arsenic. I cut off a limb in April and gathered 2.2 

 grams of the dried juice from the surface of the wound in early May 

 and found it quite rich in arsenic. It seems evident that this arsenic 

 must have been gathered from the soil by the roots, at least the arsenic 

 was at that time in motion through the tree. I have further proof 

 that the roots gather arsenic from the soil. The wood of peach trees 

 not themselves sprayed, but growing in ground that contains arsenic, 

 has been found to be quite rich in arsenic ; leaves gathered from trees 

 that had not been sprayed this season, but heavily sprayed during 

 preceding seasons, contain arsenic, and fruit grown on such trees con- 

 tain arsenic. In these cases there is no question of absorption of 

 arsenic by simple contact with the spray material. It is in the solu- 

 tions which diffuse through the tree and nourish all of its parts. This 

 seems to me to reduce the question of systematic poisoning to the one 

 question of how much arsenic a tree can tolerate. The small size of the 

 trees and their general condition of malnutrition corresponds to the 

 observed effects of arsenic in cases in which we know it to have been 

 applied and produced the injury. 



There is still another question, one which I have referred to when- 

 ever considering this subject, i. e., what may be the significance of 

 the lime in these dried juices? These orchard soils, in fact nearly all 

 of our soils, are limey; much of our land is underlaid by marl; it 

 is, however, also true that much arsenite of lime has been used for 



