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the surface of the moon, they exercise an action which at some points 

 deflects, at others inflects, light, producing what (were it not that it 

 cannot at present be asserted that any part of it is due to reflection) 

 might be termed a lunar mirage. In accordance with this general 

 law of action are observed, — the broken cusps, the dark lines, the 

 isolated spots of light of red or other colour, in total and annular 

 eclipses of the sun, — the occasional distortion of planets, the projec- 

 tion of stars upon the moon, and the fact that some of those bodies 

 are not visible at the edge of the moon's disc at emersion, but are first 

 seen at some little distance from it: all of which have been observed 

 in occultations. 



3. This action of the moon upon light is specific; being more in- 

 tense in the case of the red ray. Hence many of the phenomena are 

 more readily discernible, when a screen of that colour is employed ; 

 though not altogether invisible, if the colour of the screen be differ- 

 ent. Hence, also, the isolated spots of light, seen during a total eclipse 

 of the sun, are red ; and red stars seem to be more frequently projected 

 upon the moon's disc than others. 



4. The corona which surrounds the moon during a total eclipse of 

 the sun exhibits — 



(a) An interior bright edge, which may be due to the action of the 

 moon. 



(b) Just before the emersion, a well defined portion, which seems 

 to mark a comparative vacuum surrounding the sun. 



(c) A second portion of more decided density. 



(d) A rarer portion, exhibiting in some cases decided radiations, 

 which, as has sometimes been supposed, may be the central part of the 

 substance which produces the zodiacal light. 



Mr. Boye mentioned, that Mr. Clark Hare had communi- 

 cated to him, that, in conjunction with Messrs. Channing and 

 Gibbs, he had succeeded in producing the perchlorate of the 

 oxide of methule, by the same process which Mr. Hare and' 

 Mr. Boye himself had employed for producing the perchlorate 

 of the oxide of ethule; namely, the distillation of the dry sul- 

 phomethylate of baryta and perchlorate of baryta. 



This compound resembles, in its general properties, the perchlorate 

 of the oxide of ethule, being a colourless liquid, heavier than water, 

 and exploding with great violence on being touched by an ignited 

 body. The force of its explosion seemed, however, less than that of 

 the corresponding compound of ethule ; nor did it appear capable of 



