16 N, H. AGR. EXPERIMENT STATION. [Bulletin 183 



noted that the amounts of arsenic recovered varied from .05 

 to .30 milligram per apple, and that these figures substantiate the 

 previous records. 



In experiments at the Maine Station, reported by Woods (14), 

 winter apples were sprayed the first week in August. Sample 

 lots were carefully picked at harvest and submitted to analysis. 

 Arsenious oxid was found ranging from .034 milligram to .1 

 milligram per fruit. The concentration of material used, and 

 the amount of rain that intervened, are not stated. 



It should be pointed out that the results here discussed are 

 based on the residues remaining on the surface of the fruit. That 

 occasionally there ma}'^ be absorption of some arsenic by the 

 skin of the fruit has been noted by O'Gara (12). This, it ap- 

 pears, results from the use of lead arsenate in which the arsenic 

 and the lead are not properly combined. In such cases the skin 

 is apt to develop red or black spots. 



SPRAY APPLIED DIRECTLY TO APPLES. 



The purpose of the experiments described below was to deter- 

 mine the maximum amount of spray material that could be in- 

 duced to cling to the surface of apples. 



In the studies so far described various lots of apples were picked 

 from trees to which arsenate of lead spray had been applied. In 

 all of these cases the amount of spray material recovered on the 

 apples represented that proportion which happened to strike the 

 apple and to stick to it. It has been shown that in these cases 

 analyses disclosed the maximum amounts of .3 to .8 milligram 

 AS2O3 per apple. As noted beyond, this is to be compared with 

 the ordinary medicinal dose of 1 to 5 milligrams and the danger- 

 ous dose of 60 to 120 milligrams. 



It is conceivable that an occasional apple might be eaten 

 carrying much more than the average maximum. Such an occur- 

 rence is unlikely for the reason that an apple exhibiting such ex- 

 cessive amounts of arsenate of lead would immediately excite 

 suspicion. Furthermore, in ordinary handling, much of the 

 material would likely be rubbed off, as is shown in records quoted 

 earlier in this bulletin. However, the subject was given further 

 study. 



By preliminary trials it was found that dipping the fruit in 



