REPORT OF STATE BOARD OF HORTICULTURE. 145 



one be able to detect impurities. So far as we know but two 

 adulterants are used — gypsum and Glauber's salts. The 

 method generally given for the detection of adulteration is to 

 dissolve a small sample of the paris green in ammonia. If 

 there is any gypsum it will not dissolve, but forms a sediment. 

 Glauber's salts cannot be detected by this method, it being 

 equally as soluble as pure paris green ; but if one has a strong- 

 microscope at hand the adulterant granules can be easily 

 detected, they being white, while the pure article is green. 

 Ammonia, however, is generally a good test, gypsum being 

 most commonly used as an adulterant. 



THE ARSENITE OF LIME SPRAY. 



Professor Kedzie's formulae : 



Ingredients — Commercial white arsenic, one pound. 

 Carbonate of soda, four pounds. 

 Water, two gallons. 



Use one and one-half pints to fifty gallons of bordeaux mix- 

 ture . 



Directions — Dissolve one pound of commercial white arsenic 

 and four pounds of carbonate of soda (washing soda) in two 

 gallons of water, and use one and one-half pints to fifty gallons 

 of bordeaux mixture. The easiest way to make the solution 

 is to put both the white arsenic and carbonate of soda in a 

 gallon of boiling water and keep boiling about fifteen minutes, 

 or until clear liquid is formed, then dilute to two gallons. One 

 and one-half pints of this solution should be added to each 

 barrel of full-strength bordeaux mixture for earlier sprayings, 

 and modified bordeaux mixture for late sprayings, increasing 

 the arsenite solution gradually from one and one-half pints to 

 one quart as the season advances and foliage matures. If 

 used without bordeaux mixture or lime, it is liable to burn 

 the foliage. As there is nearly always fungus to contend with , 

 it is recommended that the two sprays be combined, with the 

 additional advantage of making the poison stick longer. Un- 

 less combined with bordeaux mixture, it is very important to 

 use enough freshly slacked lime to insure the complete decom- 

 position of arsenite of soda and formation of arsenite of lime. 

 Use six to eight pounds of quicklime, freshly slacked, to a 

 barrel of water. 



FOR CODLING MOTH. 



Paris green or arsenite of lime. First spraying, ten days 

 after blossoms have fallen, and then at intervals not exceeding 

 10 



