274 BOARD OF AGRICULTURE. [Pub. Doc. 



In the summer of 1896 I made the following experiment. 

 Having built a small platform in the crotch of a large old 

 apple tree, about fifteen feet from the ground, I took a two- 

 gallon pailful of Paris green mixture up to the platform 

 about three times a week, and sprayed the whole tree from 

 this platform, alternating occasionally with a solution of sul- 

 phate of copper. At least half of the sprayings were of Paris 

 green. This mixture was so strong as to destroy some of the 

 smaller branches near the centre of the tree. The sprayings 

 were continued till at least a dozen doses had been applied 

 between May 15 and June 15, and the canker worms were 

 pretty thoroughly destroyed. A good crop of unusually 

 fair apples began to appear, and were of three kinds, — 

 Dutch Codlings, Gravensteins and Danvers Sweets, The 

 early apples were picked about September 5 and the late 

 sweets about October 5 or later. Several of these were 

 selected, of two kinds, together with some of the leaves, 

 and were submitted to the State chemist' for analysis, and 

 he reported that not the slightest trace of either arsenic or 

 copper could be found in them. 



It should, however, be borne in mind that Paris green is 

 a deadly poison, and when used on the farm, either for de- 

 stroying the pests of fruit trees or potatoes or even larger 

 vermin, like rats and mice, the greatest care should be taken 

 to put the supply of poison out of the reach of children and 

 of animals. 



In what points do these general branches, agriculture and 

 public health, resemble each other? 



In point of usefulness to the community, agriculture and 

 public health have a great deal in common. Agriculture 

 provides the means wherewith life is sustained, the suste- 

 nance essential to the continuance of the human race. jVine- 

 tenths of all the food used throughout the world is the 

 product of agriculture. How essential it is, therefore, that 

 this most useful branch should be developed in the most 

 thorough manner and maintained in the most perfect degree. 



As it is true that agriculture maintains life, it is also true 

 that public health or hygiene protects life. Although the 

 term preventive medicine is of comparatively recent origin, 

 the practical application of the science is by no means new. 



