21(y BUniOMETRIC APPARATUS, 



VIII. 



Account of an Eudiometric Apparatus, contrked and vfed by 

 Dr, Hope, ProfoJJhr of Chemiftiy in the Univerfity of Edin- 

 burgh*. 



diomSic'a ^a' SiNCE the difcovery of the uncertainty with which tlie 

 ratus. application of nitrous gas to atmofpheric air, and other mix- 



tures, containing oxigen is attended, it has been found de- 

 firable to prefent folid or hquid fubftances for the abforplioii 

 of that principle. This, on firfi confideration, may feem 

 at leaft as eafy to be done, as to mix two gafes ; but it is by 

 no means fo, becaufe the liquids in particular poflefs a degree 

 of chemical adivity, which renders it inconvenient to im- 

 merfe the hands in them, or to expofe their furfaces to the 

 open air, efpecially when it is attempted to accelerate their 

 operation by means of agitation^ fo as to obviate the prin- 

 cipal objeftiori to their ufe, the tardinefs of the procefs. 

 - The apparatus of Dr. Hope, which he ufes in his lectures 

 and in his experiments, is at once fimple aud effeclual, and 

 I have the pleafure of inferting the fallowing correct defcrip- 

 tion with his perniiffion. 



The apparatus confiils of two bottles, which are repre- 

 fented in Plate XII, connected together in the manner in 

 ■which they are ufed ; A reprefents a fmall bottle which may 

 be nearly two inches in external diameter, and three in length, 

 having a neck and ftopper at D, and another neck as ufual at 

 C. It is deftined to contain the eudiometric liquor. B repre- 

 fents a larger bottle, which may be nearly of the fame dia- 

 meter, or rather of fomewhat lefs, but 8| inches long. The 

 •neck of B is fitted accurately by grinding into the neck of 

 A ate. 



The method of ufing this apparatus is very fimple : intro- 

 duce in the ordinary way into the bottle B, tfae air or gas 



* As the defcription at p. 61, of the prefent volume is In fome 

 ^efpefls inaccurate through hafte, and the figure, being an outline, 

 appears as if the neck of the upper veflel protruded fo far into the 

 lower, as to prevent the afcent *Df a portion of the gas after agi- 

 tation, — I have chofen rather to give an entire defcription and 

 ilrawing in this place, than adopt the lefs acceptable iftrocefs of an- 

 4|otating and correfting. 



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