408 



Among the nebulae that have been formerly observed by the author, 

 he refers to seven, which he considers as having approached very 

 near to final condensation ; and of these he observes, that we see 

 only a superficial lustre, resembling that of planets, which are opake 

 bodies, and not such as might be expected if the nebulous matter had 

 no other quality than that of shining, and were perfectly transparent. 



The author observes, that the spheroidal form which prevails among 

 nebulae, is another circumstance of resemblance to planetary bodies, 

 from which also their rotation on their axes may be inferred. 



That nebulae do really undergo successive changes, the author de- 

 duces not only from a comparison of different nebulae with each other, 

 but from a comparison of his own observations, made upon the ne- 

 bula in Orion at this time, with those which he himself made thirty- 

 seven years since. 



The figure of it, at that time, he also then observed to differ from 

 that given by Dr. Smith in his optics ; and he now remarks, that it 

 differs from the delineation given by Huygens in his Sy sterna Sa- 

 turnium. 



In the course of the gradual contraction of this nebula, Dr. Hers- 

 chel has also observed certain stars which had appeared nebulous to 

 become distinct by removal of a nebulous covering, and thence infers 

 that this nebula is certainly nearer to us than stars of the seventh or 

 eighth magnitude, and possibly not more distant than those of the 

 third. 



Notwithstanding, therefore, the extreme dissimilitude between the 

 appearance of diffused nebulosity and that of a star, they seem to 

 have a natural connexion by the several intermediate gradations that 

 have been described. A nebulosity may be conceived so dilute as to 

 be invisible till partially condensed ; a nebulosity may become con- 

 verted into a planetary nebula. The planetary nebula with uniform 

 light may, by gradual condensation of its centre, be converted into a 

 stellar nebula with bright central nucleus, surrounded by a more di- 

 lute bur ; and this at last assumes the appearance of a complete star, 

 by condensation of so large a portion of its nebulous matter, that the 

 remainder is no longer visible by the best telescopes. 



Experiments to ascertain the State in which Spirit exists in fermented 

 Liquors : with a Table exhibiting the relative Proportion of pure 

 Alcohol contained in several Kinds of Wine and some other Liquors. 

 By William Thomas Brande, Esq. F.R.S. Read June 13, 1811. 

 [Phil. Trans. 1811, p. 337.] 



An opinion having been entertained by many persons, that alcohol 

 which has been distilled from wine does not exist ready formed in 

 the liquor, but is generated during the process of distillation, Mr. 

 Brande undertook a repetition of Fabroni's experiment, on which 

 this opinion is principally founded ; but when he added four ounces 

 of dry subcarbonate of potash to eight fluid ounces of port, no alcohol 

 was separated, although some of the same wine had previously been 



