Scientific Intelligence. — Chemistry. 398 



right angles to the magnetic meridian, and that the movement 

 of the fringe from north to south takes place by the extinction 

 of streamers at its northern side, and the formation of new ones 

 contiguous to its southern side. From a variety of observations 

 which were detailed in this paper, the author infers, in opposi. 

 tion to the opinion of Mr Dalton, that the region occupied by 

 this meteor is above, but contiguous to that of, the clouds, or at 

 least to that in which aqueous vapour is condensed, so as after- 

 wards to appear in the form of clouds. The height of this re- 

 gion he estimates as in general about two thousand feet above 

 the surface ; and he is of opinion, that, while such is the lieight 

 of the lower ends of the vertical streamers, their upper ends may 

 have an elevation of two or three thousand feet more. 



CHEMISTRV. 



2. Grease of Wool. — M. Chevreul read a memoir on the fat 

 matter of wool to the Academy of Sciences, on the 8th of Sep- 

 tember 1828. The facts exposed in this memoir are detached 

 from an extensive investigation of the principal varieties of wool, 

 with respect to their immediate composition, with the view of 

 appreciating the influence of the different substances which they 

 may contain, and which are foreign to their tissue. The author 

 has extracted from Merino wool, previously washed in pure wa^ 

 ter, at least j^^ of fat matter. It was principally to this mat- 

 ter that he called the attention of the Society in the memoir 

 which he presented to it. It is formed of at least two imme- 

 diate principles, which diff*er from each other in their degree of 

 liquefaction. The one at the ordinary temperature, is like wax ; 

 while the other, in the same circumstances, is like prepared tur- 

 pentine. Both form emulsions with water, and in this respect 

 they differ from stearine and oleine, and approach the fat mat- 

 ter of the brain. On keeping them over the fire, in circum- 

 stances where oleine and stearine would be converted into soap, 

 the immediate principles of the fat matter of the wool are not 

 saponified. I'hese principles did not appear to be azotized, as 

 is the fat matter of the brain. It is remarkable that the tissue 

 of wool which has been deprived of jYjj of fat matter, does not 

 shew itself much more apt to be dyed than it was before, as 

 might have been imagined, from what is admitted respecting the 



