1891.] ESSAYS. 87 



stand, that was sent out from the Agricultural Department last 

 spring. 



The French use such pumps very largely ; but Americans will 

 make little use of them where much work is to be done, when 

 the horse can be made to draw the liquid for them. 



NozzLKS. A nozzle to distril)utesuch liquids as the Bordeaux 

 mixture must have an adjustable opening at the end. Among 

 those to be found in our market are the " Perfection," the 

 " Nixon," the " Cyclone," the " Vermorel," and many others. 

 Professor L. H. Bailey of Cornell University has contrived a 

 clamp which is attached to the end of a common rubber hose, 

 by the pressure of which the size of the opening is quickly ad- 

 justed. Whatever the nozzle used, it must be attached to a 

 long pole to distribute the liquid most evenly at the top of high 

 trees. 



Many interesting facts have been brought out in the work of 

 the many experiment stations of the country which could not be 

 referred to in the previous discussion, and I have therefore 

 introduced them here. 



It seems pretty well settled that of the arsenites, Paris green 

 gives the best results as an insecticide. 



That the longer the mixture containing the arsenites stands 

 the greater the injury from soluble arsenic. 



That the foliage of the peach, plum and cherry is more sus- 

 ceptible to injury than that of the apple and pear. 



That the injury varies with the varieties, some being more 

 susceptible than others. 



That young leaves are less injured than those fully developed, 

 and are more injured on weak trees than on those that are 

 vigorous and healthy. 



That Paris green cannot be used alone with safety stronger 

 than one pound to three hundred gallons of water, but with the 

 lime mixture it may be safely used at one pound to from fifty to 

 two hundred gallons. 



That the foliage is most injured when kept constantly wet l)y 

 light rains or foggy weather, but that heavy rains lessen the 

 injury. 



