Determination of the Altitude of Great Whernside. 209 



The preceding experiments are instructive, as they forbid 

 us to lose the preservative principle contained in carbonic acid 

 gas, and moreover explain the transit into the acetous chano-e. 

 Carbonic acid ^as is expelled in vinous fermentation ; and be- 

 ing thus quit of its counterforte, it is prepared at a favouring 

 temperature to glide into that of the acetous, the step which 

 precedes the last, — the concluding act — the putrefactive fer- 

 mentation, which resolving the materials into ultimate and 

 elemental forms, finishes the conflict, and the whole sinks into 

 undisturbed repose. 



It may not be irrelevant to mention the following experi- 

 ment connected with the question of vinous fermentation ; — it 

 verifies a somewhat similar one, made, if my memory serves 

 me well, some years ago, by a continental chemist. A deep 

 conical ale glass was nearly filled with Port wine, and its ori- 

 fice closed by a slip of bladder, and properly secured. At 

 the end of 226 days the liquid had diminished to one half its 

 original volume. The colour was deeper than before, and it 

 burnt in all respects like -proof brandy. By this method may 

 Mr. Brande's interesting conclusions respecting the quantity 

 ot alcohol contained in wines receive verification. 

 I am gentlemen, 



Yours most obediently, 



J. Murray. 



XLV\ Determination of the Altitude of Great Whernside : 

 with Remarks on teirestrial Refraction. By A Corre- 

 spondent. 



To the Editors of the Philosophical Magazine and Journal. 



SINCE my last communication, 293 observations made with 

 the horizon sector, at fifteen different stations, have fur- 

 nished data to prove, beyond a doubt, the incorrectness of 

 the altitude of Great Whernside, as given in the Ordnance 

 Surve}% It is the more desirable to enter into the details, as 

 the accuracy of a forthcoming survey of the upper part of 

 Wharfdale will in a great measure depend on the exact de- 

 termination of the elevation of this mountain, the loftiest of 

 the valley. 



It is almost superfluous to premise, that without an ade- 

 quate knowledge of the nature of refraction, the most careful 

 observations made with unexceptionable instruments are but 

 vague and per})lexing materials for calculation. May I there- 

 fore be allowed to disjilay my present store of information on 



\'ol. 61. No. 299. March 1823. D d this 



