1890.] PUBLIC DOCUMENT — No. 4. 15 



wormy, would sell for $2.00. Now, this proportion will not 

 hold. The No. 2's under the same circumstances bring from 

 $1.00 to $1.50. This comes about from the relatively large 

 proportion of the inferior fruit, which has constantly in- 

 creased, and, in the absence of an effectual preventive, must 

 continue to increase. In years of small crops nearly all of 

 the fruit will be of this poor character, and it is only when 

 the production is very large that any considerable propor- 

 tion is free from insect injuries. Various remedies have 

 been proposed, which are partially effective ; but I know of 

 only one that is worthy of serious consideration generally. 

 Arsenical preparations, if properly and persistently applied 

 at the right time, will be found to be more valuable for this 

 purpose than any other treatment that has yet been brought 

 forward. There are three forms in which arsenic has been 

 used : viz., arsenious acid, or white arsenic ; Paris green, or 

 the arsenite of copper; and London purple, a waste product 

 of somewhat uncertain composition. I have experimented 

 a good deal with white arsenic, but find that it cannot be 

 depended upon at any strength which will save the foliage 

 from injury. Paris green is safe, and may be sucessfully 

 used with sufficient care ; but I give preference to London 

 purple. Paris green is so heavy a powder that it settles 

 almost at once in the water, and, unless constantly stirred, 

 it is impossible to distribute it evenly over the tree. Lon- 

 don purple is much better in that respect, and probably for 

 that reason is more effectual and gives better satisfaction. 

 It should be used at the rate of one pound of the purple to 

 from one hundred and fifty to two hundred gallons of water. 

 If stronger than the first, it will be liable to burn the foliage 

 in spots ; and, if weaker than the latter, it is only partially 

 efficient. The foliage of pears is more tolerant of it than 

 apples. An even teaspoonful to two gallons of water is about 

 right, but as they vary in capacity, I would advise measuring 

 your teaspoon, so as to make it definite. The liquid can be 

 best applied by means of an ordinary brass hand-syringe, 

 with a fine rose. It should be thrown with force in order 

 to form as fine a spray as possible, into and above the 

 tree from every side, so as to wet the whole foliage. 

 That which falls upon the ground is useless, but no harm 



