350 



the sun's rays. Some may think the change referred to a molecular 

 or chemical one ; and others, wiser than the rest, refrain from any 

 explanation, waiting for a larger multiplication of experiments, and a 

 greater accumulation of facts, before educing any satisfactory law of 

 Natm-e which governs these curious and interesting phenomena. 



Mr. Gaffield makes no pretensions to any discoveries, unless it be to 

 the very rapid change in glass observed in our climate in July, but only 

 gives the result of his experiments, in the hope that the great interest 

 now manifested in the subjects of light and heat may lead others to 

 examine the matter, to repeat the same experiments in other countries, 

 and to give the world the result of their researches, and enable the 

 learned and scientific men of the age to explain this remarkable 

 power and action of the sun's rays. 



It should be remembered that Mr. Gaffield submitted his 

 sjjecimeiis to the most severe tests by placing them where 

 they received reflected as well as transmitted light and heat. 

 The change in glass, when glazed in the windows of our 

 dwellings and stores, is so much more gradual, that it very 

 rarely attracts the attention of observers, except in a marked 

 variation from white to jDurple. 



Mr. F. W. Putnam said, that, at the last meeting of the 

 Essex Institute in Salem, Mr. Ordway of Ipswich gave a 

 communication upon the habits of the canker-worm {Anisop- 

 eryx vernata Harris), in connection with a patented article 

 to prevent the insect from laying its eggs upon trees. 



Mr. Ordway had spent several years in watching the habits of the 

 canker-worm, and had tried many ways to jjrevent the ravages of the 

 insect, but had not been successful until the present season, when he 

 met with success by fastening a rim of zinc to the tree by a piece of 

 cloth tied round the tree above, and arranged in such a manner, that 

 the female moth, in crawling up the tree, came in contact with the 

 cloth, and was forced to crawl down over it, and thus be brought 

 in contact with the rim of zinc. Upon the under side of the zinc- 

 rim a narrow band of zinc was soldered, so as to make an acute 

 angle. When the female moth came to the rim of zinc, she would 

 endeavor to pass over it, and, to do so, would have to come in 

 contact with the band soldered to the rim ; and, in attempting to pass 

 over this, she would invariably fall to the ground. It was ascertained 

 that the particular angle made by the soldering of the band to the 

 rim could not be got over by the moth, though all other angles could 



