Plaiit Diseases and Insects. 87 



it ranks third. But by analysis it was found to contain a 

 large proportion of free soluble sulphates, and consequently 

 there is a manifest possibility of its burning the foliage, es- 

 pecially if the solution on the leaves is concentrated by sev- 

 eral applications, or by the carelessness of the operator. If 

 more lime is added it unites with the sugar and is a total loss, 

 and still the solution may not be completely saturated. 



''The name improved Bordeaux mixture could more appro- 

 priately be applied to a preparation, the formula of which has 

 been given by Mr. Duchein. It combines the merits of the 

 Bordeaux mixture and the eau celeste. Mr. Duchein prepares 

 the Bordeaux mixture according to the formula already given, 

 but uses as little water as possible. The lime is in excess and 

 this facilitates the operation. Then he adds as little ammonia 

 as possible, just enough to obtain a blue coloration in the su- 

 pernatant liquid. All that is then necessary is to add suf- 

 ficient water to produce a hectolitre of the liquid. This is a 

 simple and cheap preparation, and perhaps the only objection 

 to it is its want of adhesive power." 



Insects. Some of the most important results of the year in 

 economic entomology have been collated for me by Professor J. 

 B. Smith of the New Jersey Experiment Station : 



"The plum-curculio was one of the favorite subjects of 

 investigation during the 3^ear, Ohio, Michigan, Iowa and New 

 Jersey having devoted considerable attention to it. In Ohio, 

 Weed carried on his plum spraying experiments 'under ordi- 

 nary commercial conditions,'* spraying one-half of an orchard 

 of 900 plum trees, and jarring the other. The result was extra- 

 ordinary. Of the sprayed trees not more than 3 per cent, of 

 the fruit was injured ; of the jarred trees not more than 4 

 per cent. There is no statement of what neighboring orchards 

 were like, and this record stands in strong contrast to the results 

 attained by Gillette and Cook. Cook, after strongly recom- 

 mending the arsenites for the curculio,t tried his own recom- 

 mendations most thoroughly, and with a most deplorable lack 

 of success. X Although treated in the most careful manner, every 

 plum on the sprayed trees was injured. He adopts now the 

 rather startling theory that the curculio is a friend, because it 



*Bull. 8, vol. iii. Ohio Exp. Sta. fBull. 53, Mich. Exp. Sta. 



tSee a thorough discussion of arsenites for the plum curculio in Annals Hort. 1889, 61. 



