The contents of a rabbit's stomach were digested in distilled water, 

 and the clear portion of liquid thus obtained divided into four parts. 

 The first was evaporated to dryness, and the quantity of muriatic 

 acid present in the residuary fixed salts determined by nitrate of sil- 

 ver ; the second was supersaturated with potash, evaporated and de- 

 composed by nitrate of silver as before, by which the total quantity 

 of muriatic acid in the fluid was ascertained ; the third was neutral- 

 ized by a solution of potash of known strength, and the required 

 quantity accurately noticed. This gave the proportion of free acid 

 present ; and by adding this to that in union with a fixed alkali, as 

 above determined, and subtracting the sum from the total quantity 

 of muriatic acid present, the proportion of acid in union with ammo- 

 nia was estimated. But as a check to this result, the third neutral- 

 ized portion was evaporated to dryness, and the muriate of ammonia 

 expelled by heat ; the quantity of muriatic acid left in union with the 

 fixed alkali was then determined as before ; and by subtracting this 

 from the total quantity, the quantity in union with ammonia was 

 determined. 



From such experiments the author concludes, that no inconsider- 

 able quantity of unsaturated muriatic acid exists in the stomachs of 

 animals during digestion; and from the examination of the fluid 

 ejected from the human stomach in a case of dyspepsia, he infers 

 that there also the muriatic acid performs the same office. 



On the North Polar Distances of the principal fixed Stars. By John 

 Brinkley, D.D. F.R.S, 8$c. Andrews Professor of Astronomy in the 

 University of Dublin. Read December 18, 1823. [Phil. Trans. 

 1824, p. 50.] 



The author observes, that of the recent catalogues that have 

 been formed of the principal fixed stars, two, those of Dublin and 

 Greenwich, agree very exactly. That of M. Bessel differs con- 

 siderably ; but the differences are such that they would agree by a 

 modification of the co-efficients of refraction employed for correcting 

 the observations. Mr. Pond, he says, has applied the refractions of 

 Bradley to the instrument of Dublin ; he himself thinks it more safe 

 to determine the refraction for each place from its own instruments ; 

 and he objects to the reasoning by which Mr. Pond has endeavoured 

 to prove the existence of a flexure in the tube of the instrument of 

 Dublin. 



Dr. Brinkley makes the mean difference of the stars of Greenwich 

 and Dublin for 1813 only a few tenths of a second; for 1823, still 

 less. Neither the Dublin Catalogue, nor any other more extensive 

 comparison, affords, in his opinion, a confirmation of the hypothesis 

 of a general southern motion, which he is therefore inclined to attri- 

 bute principally to a slight inaccuracy of the Greenwich Catalogue 

 for 1813. 



The comparisons unfavourable to the southern motion are those 

 of Bradley' s observations at Wanstead, in 1728; and some French ob- 



