30 STATE HORTICULTURAL SOCIETY. 



want tbe poisonoiis i)roperty of copper combined witli the poisonous prop- 

 erty of arsenic, you can get the arsenite of copper, which is more poison- 

 ous than the arsenite of lime. This has been tested as an insecticide. I 

 have prepared some of this arsenite of lime and we have used it with 

 equally as good results as from Paris green. 



DISCUSSION. 



Prof. Taft: It gets the potato bug right along. It is fully as effective 

 as Paris green. We used a pound in four hundred gallons for spraying 

 fruit trees, only half the amount we used of Paris green. We also used 

 it with lime alone. By using the test Dr. Kedzie speaks of you can detect 

 the presence of free arsenic. If a person uses this instead of Paris 

 green, I would test either in this way or by boiling before using. Bul- 

 letin No. 124. from the Experiment Station, gives this method of prepar- 

 ing it, and if the directions there given are followed, you will have no dif- 

 ficulty. Suppose you take your arsenic and lime together, and boil one 

 pound of arsenic to two pounds of lime. You have your complete mix- 

 ture in the form of arsenite of lime. The (piickest and safest and easiest 

 of all ways is to boil it with sal-soda, and add that to the slaked lime, and 

 a pound of lime will precipitate a pound of arsenic as arsenite of lime. 



Q. Would it be necessary to test with the sulphuretted hydrogen? 



A. If I take some of this and stir it up, to see if it contains any arsenic, 

 you see that no arsenic is in solution. I add to this a little acid to 

 dissolve the lime, and bring the whole of the material into solution, and 

 now the reaction for arsenic is very strong. If you are going to test this 

 material you must be sure to get a clear solution and have no suspended 

 arsenite of lime. The beauty of this spraying mixture is that the whole 

 of the arsenic is in an insoluble form. You may be perfectly safe in boil- 

 ing the material (white arsenic, 1^ ounce) in sal-soda (five ounces) and 

 adding it to the slaked lime (two pounds). Dilute to forty gallons of 

 water. 



.Mr Morrill : A great many people are using London purple because it 

 is cheap; but, as it is being adulterated it may be that it will not kill at 

 all. Do yon make any test to find out this killing property? Not one 

 man in the state will know of that for years. The fact that London 

 purple is being adulterated is causing a great many people damage, and 

 it is worth investigating. A neighbor used it and he could not kill any 

 potato bugs. He put it on four times its strength. 



Dr. Kedzie: How many are going to learn about th.at? We had bet- 

 ter begin to use the arsenite of lime, straight. 



Mr. Morrill : Paris green seems to have about as good effect as ever. 



A member: Last year, in our neighborhood, we had Paris green that 

 would not kill unless we used three or four times the usual amount. 



Q. Is it practical to have this as a commercial article, so we could get 

 it instead of having to make it ourselves? 



■ A. It is bulky, and if the farmers know just how this is made I don't 

 see why they can't make it. There is a swindle on Paris green. A lot of 

 conscienceless men got together and took advantage of the trust. We 

 know that this is perfectly reliable and safe. I don't see why this news 

 can't go through the community. Why could not some one person manu- 



