292 Mr. J. Glaisher on the Meteor which appeared 



After having so long taken up the attention of the Academy 

 with the question of isomerism, which was the principal object 

 of the memoir of M. Pastern*, we must give a more brief sum- 

 maiy of the second part, in which he has presented in a few 

 pages some comparative remarks upon the molecular constitution 

 of the malic and tartaric acids. It is not because he did not 

 find very great analogies and very curious phseuomena that the 

 author has had reason to mention them. Thus he has proved 

 that the malic acid is, like tartaric, very considerably affected by 

 the nature and proportions of the solvents in which it is observed ; 

 that this takes place instantaneously with boracic acid, in all 

 cases with singular differences in the mode and even in the direc- 

 tion of the dispersions. But in the first place, in order to 

 render appreciable the consequences which the results of these 

 optical examinations may suggest or legitimize, it would be ne- 

 cessary to preface them by other remarks which relate to the 

 pecidiarities of the action which tartaric acid exercises upon 

 polarized light, and that would extend our report beyond conve- 

 nient limits. Again, we have a still stronger motive, which is, 

 that the small quantities of malic acid which M. Pasteur had at 

 his disposal did not admit of his foUowdng up the optical study 

 mth all the detail which he would have desired ; and the same 

 difiiculty has equally restricted our capability of confirming ex- 

 perimentally the general results which he has announced. But 

 we learn, that, by the kindness of M. Liebig, he is now provided 

 with an abundance of this acid; so that he will be able to resume 

 the complete study with that zeal which distinguishes him ; and 

 we shall await the time of its completion before specially enter- 

 taining the Academy with an account of what he has already 

 been able to discover with regard to this subject. 



XLV. On the Meteor which appeared on Thursday, the 12M of 

 August 1852, at about 9^ 20'^ p.m. Greenwich Time. Brj 

 James Glaisher, Esq., F.R.S. 



To the Editors of the Philosophical Magazine and Journal. 



Gentlemen, 



THE brilliant meteor described in your Journal of last month, 

 as seen at Sidmouth, was remarkable in many respects. 

 I beg to send you the following particulars relating to it, with 

 the results of some calculations I have made to determine its 

 distance from the earth. 



I. From Belfast. L. P. Duke, Esq., kindly favoured me with 

 the following particulars : — 



