,«UDIOMETRIC APPARATUS. 211 



till it is full ; then fill A with the abforbing liquor, for exam- Dr. Hope's eu- 



I -1 r . ' ,■ /- 1 I n 1- 1 • 1 T-. TT diomemc appar 



pie with a lolution ot lulphuret ot lime, which Dr. Wope^j^^^j^ 

 commonly employs, and covering the mouth with a flat piece 

 of glafs, plunge it under the furface of water, and there in- 

 lert the neck of B. 



The compound veflel is then removed from the water, and 

 inclined till a fufficient quantity of the liquor flows into 

 B. It is now well (liaken, and the agitation ought to be con- 

 tinued till the abforption is compleated — Left the diminution 

 of the denfity of the included elaftic fluid fliould retard the 

 abforption of the oxigenous portion ; from time to time the 

 apparatus, in the pofition in which it is reprefented in the 

 figure, is to be placed in a plate full of water, and the ftopper 

 D is to be loofened, or fo far withdrawn, as to allow this 

 fluid to enter to fill the place of the abforbed gas. — By this 

 admixture of water the liquor is diluted, but not to fuch a 

 degree as in any meafuie to interrupt the advancement of 

 the procefs, unlefs indeed when the gas abounds very much ia 

 oxigen. 



When a gas of this defcription is the fubjeft of experiment, 

 it may be proper to ufe an apparatus, of which the bottle A is 

 made of greater capacity in relation to the fize of B, than in 

 the proportion already afligned. 



As foon as it is obferved, that after reiterated agitation, and 

 opening the ftopper D, the liquor does not rife higher, the ab- 

 forption may be confidered as compleated, and the operation 

 may be finiflied by allowing the inftrument to regain its ori- 

 ginal temperature, in cafe, from want of due precaution, it 

 may have been affeded in this refpeft by the warmth of the 

 hand in the courfe of the experiments. 



If the bottle B be graduated, the amount of the abforption 

 may be determined at once, by plunging the apparatus into 

 water to the level of the included liquid, and removing the 

 ftopper, otherwife the refidual gas may be transferred into a 

 tube, exprefsly graduated for meafuring gafes. 



By this convenient contrivance, we fee that the liquid is 

 economized and the celerity, neatnefs, and precifion of ex- 

 periment are enfured. The fize here mentioned is very well 

 adapted to the purpofes of publie exhibition, but it is almoft 

 needlefs fo remark, that it may, and in general ought to be 

 made confiderably fmaller for the ordinary eudiometric expe- 

 rimeqts. 



P2 Dr, 



