154 The Canadian Horticulturist. 



PARIS GREEN WITH THE BORDEAUX MIXTURE AND 

 AMMONIACAL COPPER CARBONATE. 



HE efficacy of certain spraying fluids for combating injurious insects 

 ^ and fungus diseases of plants is now well established and recog- 

 nized. Of the insecticides, Paris Green in water is perhaps the most 

 important ; of the fungicides, the Bordeaux mixture and the 

 Ammoniacal Copper Carbonate are the most widely known and 

 >^ used. 



At times, more especially in orchard work, both an insecticide 

 and a fungicide are required. Consequently, there have been efforts made for 

 several years past to prepare a fluid which would combine these functions. The 

 application of such a fluid, if efficaceous, would result in a considerable saving 

 of time and labor. The simplest method, and one that at once occurs to those 

 using spraying fluids, is to add the Paris Green, in the proper proportion to the 

 fungicide. Such fluids or mixtures using Bordeaux and Ammoniacal Copper 

 Carbonate, have been tried for several seasons, and, as might have been ex- 

 pected, various results have been reported. In some instances, failure to pro- 

 tect from the ravages of insects and fungous foes is said to have attended these 

 trials, and further that the failure is to be attributed to a solution or decompo- 

 sition of the Paris Green in the fungicide fluid. To ascertain if such a decom- 

 position or solution actually occurred, the following experiments were made : 



I. Diluted Bordeaux mixture with Paris Green was prepared from the 

 formula 



Copper Sulphate 4 lbs. 



Lime 4 lbs. 



Pans Green 4 oz. 



Water 50 gallons. 



The freshly burnt lime was slaked and stirred with water until the whole 

 was of the consistency of cream. 7'his was then stirred into a vessel containing 

 the dissolved Copper Sulphate and made up to the required volume. The 

 Paris Green was then added and the mixture thoroughly stirred. 



{a) After keeping the mixture thoroughly agitated for two days, a portion 

 was withdrawn and filtered. The clear filtrate was then submitted to careful 

 chemical analysis, but not a trace of arsenic could be detected. 



{b) For a further period of a week, the mixture was kept agitated and 

 then another portion withdrawn and filled. Analysis did not reveal the presence 

 of arsenic in the filtrate. '^ 



We are therefore justified in concluding that under the conditions here 

 stated no decomposition or solution of the Paris Green takes place in the Bor- 

 deaux mixture, and therefore that the efficacy of this arsenical poison, as an 

 insecticide, is not thereby lessened. 



