186 M. Chevreul on Fatly Bodies, and [Sept. 



side of the sun, as the moon always makes the first impression 

 on the sun's disc on that side. 



The whole duration of the eclipse will, at all these places, be 

 rather more than two hours and three quarters. But the dura- 

 tion of the annulus will not, in any place, exceed six minutes ; 

 and in some places (at the confines of the umbra) it will be 

 momentary. The nearer the spectator happens to be to the 

 centre of the path of the moon's umbra, the longer will the 

 annular appearance continue. 



(To be continued.) 



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Article V. 



Researches on various Fath/ Bodies, and particularly on their 

 Co?nbinations with Alkalies. By M. Chevreul.* 



After noticing the imperfect state of our knowledge on the 

 subject of saponification, and the mistaken ideas that have been 



* M. Chevreul has, for some years, been assiduously directing his attention to 

 this subject, and has, from time to time, published an account of his experiments 

 in a succession of papers inserted in the Annates de Chimie; the first of them 

 appeared in the 88th volume of that work ; they have been continued at intervals ; 

 and, as we learn from the number for April last, are not yet completed. We 

 propose to give an abstract of the whole ; but as the contents of the earlier of them 

 may probably be known to many of our readers, we shall pass them over iu a 

 more brief manner. 



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