I78 MAINE AGRICULTURAL EXPERIMENT STATION. I9OO. 



arsenoid or arsenite of copper has been quite extensively intro- 

 duced by the Adler Color and Chemical Works. A sample 

 examined by the California Station was found to carry 53^ per 

 cent of combined and nearly 8 per cent of free arsenious oxide. 

 As previously stated, copper arsenite if pure would carry about 

 53 per cent of combined arsenious oxide. 



The Adler Color and Chemical Works are experimenting- with 

 different arsenoids with the hope of obtaining compounds which 

 will be as effective and at the same time cheaper than Paris green. 

 Four of these materials called Arsenoids Xos. 2, 3, 4, and 5 were 

 used in these experiments. In each case they were applied four 

 times with Bordeaux mixture at the rate of one-half pound of 

 arsenoid to the acre. 



The manufacturers make the following statements to us rela- 

 tive to these materials. 



"No. 2 arsenoid is a compound containing arsenious acid, cop- 

 per and iime and is made by treating arsenite of soda with sul- 

 phate of copper and lime. This gives an absolutely neutral 

 combination of salts which is not likely to do any damage to 

 foliage even when used in very strong solution. Could be sold 

 for about 8 cents per pound. We have hopes that this will prove 

 in every respect a most desirable insecticide. 



"No. 3 arsenoid is made by treating a solution of acetate of 

 lead with arsenate of soda and at the same time making an 

 admixture of arsenite of copper. Cost of this would be about 

 14 cents per pound. 



"No. 4 arsenoid is made by precipitating acetate of lead with 

 arsenate of soda and at the same time adding arsenite of soda 

 precipitated with lime, along with an admixture of arsenite of 

 copper. The resulting compound consists of arsenite of lead, 

 arsenite of lime and some arsenite of copper. This could be sold 

 for about 10 cents per pound. 



"No. 5 arsenoid is made by precipitating arsenite of soda with 

 sulphate of copper and lime, producing an arsenite of copper and 

 lime. This could be sold for about 10 cents per pound." 



There was not much difference to be seen in the way the dif- 

 ferent arsenoids acted. None of them at the rate used burned 

 the foliage and they all killed the bugs practically as well as Paris 

 green. The arsenoids are more bulk}- and on this account are 



