151 



salts, stated in last year's report, have been corroborated, while, in addition, the 

 experiments made this year go to show that copper sulphate and "agricultural blue- 

 stone " are far more eflScacious for the prevention of the development of smut than 

 sijlphate of iron. 



Fertility of Soil not injured by Spraying. — An impression was going abroad that 

 the copper solutions used in spraying for fungus diseases was affecting disastrously 

 the fertility of our soils, and an article to this effect lately appeared in one of our 

 leading papers. I have, therefore, written a short chapter, discussing the nature of 

 the application and the chemical changes involved. These all go to show that the 

 assertion that the soils are "poisoned " by this useful operation is fallacious. 



Insecticides with Soap Solution. — There are many cases in which it is desirable to 

 apply the insecticide Paris green in soap solution. The question then arose: Is the 

 effect of Paris green weakened by the soap ? As I was requested to give an opinion 

 on this matter, I undertook a number of experiments, the results of which are 

 enumerated in this report. They show that the efficacy of this insecticide is not 

 materially affected by being applied in soap solution. 



Sprayed Apples are not poisonous. — The last chapter of this report contains the 

 results of an experiment undertaken to afford scientific proof for the refutation of the 

 statement that "apples sprayed for codling moth are dangerous to health, if not 

 positively poisonous, owing to the presence of arsenic of the Paris green used in the 

 operation of spraying." 



Some few months ago a statement to this effect appeared in an English horti- 

 cultural paper. This report received wide circulation in the press generally, and 

 was calculated to do much harm to the Canadian export apple trade. [ therefore 

 made a very careful analysis of apples that had been twice sprayed (Paris green 1 lb., 

 water 200 gallons), and though the process employed was one of extreme delicacy, 

 not a trace of arsenic could be detected. This result gives additional support to the 

 statement that the suspicion that Canadian apples are poisonous is entirely without 

 foundation. The publication of this positive proof of the absence of arsenic in these 

 sprayed apples should serve to assure those in England, as well as Canadian horti- 

 culturists and apple exporters, that this practice, so useful in prevening the ravages 

 of the codling moth, does not result in poisoned apples. 



I again with very much pleasure record my thanks and indebtedness to Mr. 

 Adolph Lehmann, B.S.A., the assistant chemist, for the valuable aid he has rendered 

 me. Mr. Lehmann has devoted himself most assiduously to the work of the depart- 

 ment since his appointment, and many of the analytical data contained in this report 

 are the result of his ability and industry. 



I have the honour to be. Sir, 



Your obedient servant, 



FEANK T. SHUTT, 



Chemist, Dominion Experimental Farms, 

 Chemical Laboratories, 



Central Experimental Farm, 

 Ottawa. 



