34 



COST OF THE EXPERIMENT. 



So much for the dance; now what must we pay the fiddler? Do 

 apples raised with a force pump and fed on poison, possibly cost 

 more than their market price'? Excluding interest on the cost of 

 the apparatus, which is too slight to be taken into account, the ex- 

 penses of application are covered by the cost of labor and material. 

 The former, in our case, amounted, for the season, to the hire of 

 two men for thirty-two minutes per tree, and the latter reached a 

 sum of *22| cents per tree, the total amount of Paris green for each 

 tree being six ounces for the season — here reckoned at 50 cents per 

 pound. It is evident that the Paris green was used by us in exces- 

 sive quantity, and we shall soon find that the trees were sprayed 

 more frequently than was necessary or expedient. Further, if special 

 contrivances were used for the distribution of the fluid in an orchard, 

 the time per tree for a single spraying would doubtless be consid- 

 erably lessened as the laborers became expert at the work, so that 

 I do not doubt, upon the whole, that 10 cents per tree, for the sea- 

 son, is a fair estimate of the necessary cost of a sufficient use of 

 Paris green to give the full efl'ect of the remedy. 



DAMAGE TO THE TREES. 



Used with the strength and frequency of our experiments, the 

 Paris green conspicuously burned the leaves. Probably from one 

 third to one half of those upon the experimental trees were more or 

 less scorched and withered at the edges, and a greater part of the 

 leafage fell in autumn somewhat prematurely. In fact, our notes 

 show that the leaves from one of these trees were falling rapidly 

 July 31, the tree treated with London purple being similarly affec- 

 ted. We had some evidence that the fruit itself was injured in our 

 case, a surface discoloration and subsequent local rotting of the apples 

 being most evident on that side of the tree towards the prevailing 

 winds with which the greater part of the spraying was done. 

 Thus the rather nice question is raised, in our experiments, whether 

 our gain in apples was not lost in damage to the tree. We had 

 saved some fragments of the golden egg, but had we not possibly 

 crippled the goose by our heroic surgery ? It is not to be presumed, 

 however, from the above, that this damage to fruit and foliage is a 

 necessary consequence of the use of Paris green. It is doubtless to 

 be attributed partly to the purposed excess with which we applied 

 the poison, and partly to our lack of experience in spraying in the 

 beginning of the season. 



DANGERS TO STOCK. 



It of course goes without saying that no poisonous substance 

 should be applied in an orchard to which stock is admitted. 



DANGERS TO HEALTH. 



Keeping in mind the fact already repeatedly alluded to, that our 

 u&e of Paris green in these experiments was excessive, it will be 

 worth while to report the result of a chemical analysis. From one 



