70 MASSACHUSETTS HORTICULTURAL SOCIETY. 



Mr. Strong thought that if that were the case, prevention, if 

 possible, would be much better than cure. 



F. L. Temple inquired if the fungicides are not injurious to 

 the trees. 



Professor Mayuard replied that it is only when the remedies 

 /fire too strong that any harm is done to the trees. 



Mr. Temple related an experience in treating Prunus Americana 

 with salt. The ])lack wart was cut out and the wound covered 

 with cloth which was first dipped in pickle from a pork barrel. 

 The wetting was repeated often and followed up several weeks 

 •with such good effect that the trees were kept in bearing condition 

 for years by this method. 



Mr. Philbrick spoke of a rust which had affected the leaves of 

 maple trees over a considerable area in this State, and asked for 

 information about it. 



Professor Majmard replied that the rusts or lilights of many 

 forest trees are of similar nature to the apple scab, and referred to 

 the "Journal of Mycology," Vol. 2, page 13, 1886, where the rust 

 mentioned l)y ]Mr. Philbrick is shown to be caused by Phyllosticta 

 acericola, which was found in New England in 1874, and in 

 various other parts of the United States at sundry dates since ; 

 that it attacked Maples, and that other somewhat similar fungi 

 affected Poplar trees and some other sorts. The effect of their 

 presence in all cases is much like that of the apple scab. 



AYilliam H. Hunt asked if white arsenic is just as good as the 

 crude form for use as a remed3\ 



Professor Maynard replied that white arsenic is just as effica- 

 cious as the other forms mentioned ; but if the preparation were 

 allowed to stand a while after being mixed, the arsenic, by the 

 evaporation of the liquid, would become very much stronger in 

 proportion and the longer it remained unused the greater would be 

 the proportion of arsenic. Tlien, if used again without the 

 necessary addition of Avater, it would be liable to injure the plants, 

 and might destroy all the foliage. But another objection to the 

 use of white arsenic for this purpose is that it bears so close a 

 resemblance to otlier and harmless substances that there is danger iu 

 having it about the house, where it may be used in place of one of 

 those, and produce fatal effects. Paris green mixtures also 

 become injurious by standing unused, and the more so in propor- 

 tion to the time thev staud. 



