EXPERIMENT STATION WORK WITH INSECTICIDES. 259 



green in limewater yielded 12 bushels less than those treated with 

 Paris green in water, but it is not certain that the addition of lime 

 caused this difference. The treatment with Paris green in Bordeaux 

 mixture gave slightly larger yields than treatment with Bordeaux 

 mixture alone. At the same time arsenite of soda stock solution pre- 

 pared by the Kedzie fornuila was applied with limewater and also 

 with the Bordeaux mixture. In limewater this arsenite injured 

 potato leaves severely, although 2 pounds of lime were used for each 

 pound of the stock solution. There was no apparent injury, how- 

 ever, when the same amount of arsenite of soda \vas used in the 

 Bordeaux mixture. It is maintained therefore that the combination 

 with Bordeaux mixture renders arsenite of soda comparatively safe. 

 Nevertheless, potatoes treated with Bordeaux mixture alone yielded 

 34 bushels per acre more than those treated with arsenite of soda in 

 Bordeaux mixture. From these experiments it appears that Paris 

 green is not injurious to potato leaves if appli'?d in ordinary quan- 

 tities in limcAvater or Bordeaux mixture. Paris green also has some 

 fungicidal value. Arsenite of soda, however, is dangerous for use on 

 potatoes except when combined with Bordeaux mixture. 



The use of arsenical poisons in combating insects on cabbage in 

 Kentucky led to some misgivings regarding the possible dangers of 

 this method to human beings." Several cases of supposed poisoning 

 from eating sprayed or dusted cabbage were reported, and an attempt 

 was made to investigate these cases. Little satisfactory evidence 

 could be obtained in any case. The station undertook a number of 

 experinu'uts for the purpose of testing this matter directly. In these 

 experiments cabbage was sprayed from two to four times with Paris 

 green at the rate of 1 i)ound to 140 gallons of water and arsenate of 

 lead at the rate of 2 pounds per 100 gallons of water. Cabbage heads 

 were then analyzed to determine the amount of arsenate present. 

 P'rom these analyses it appears that only minute particles of arsenic 

 were present. In general, two applications of arsenicals were less 

 effective than four. A lime-resin mixture containing resin, lye, fish 

 oil, and Paris green was compared with the pure arsenical treat- 

 ments and was found to have no i)articular advantage over the latter. 



At the New York State Station '' a lime-resin mixture containing 

 5 pounds resin, 1 pound concentrated lye, and 1 pound fish oil per 

 5 gallons of water was found to constitute a very satisfactory stock 

 solution from which to prepare an insecticide for the treatment of 

 cauliflower and cabbage. When one gallon of this stock solution was 

 mixed with '.\ gallons milk of lime, one-fourtli pound Paris green, and 

 K) gallons of water it was found that the use of this insecticide was 



a Keutucky Sta. Bui. 114, ?> >'qw York Sta. Bui. 144, 



