Atcoiint of a new Eudiometer. \ 1 9 



of others, and to make some new ones, I soon found what 

 every one who has been engaged on the same subject must 

 have experienced — -that an apparatus more commodious than 

 has yet been proposed, and at the same time capable of giving 

 correct residts, with the greatest minuteness, was stil! a de- 

 sideratum in eudiometry. To detail the various ideas that 

 presented themselves on the subject, would be an unneces- 

 sary encroachment on the time of this society ; but as 1 at 

 last succeeded in contriving an instrument posscssmg the 

 above properties in a very eminent degree, I flatter myself 

 I shall not be thought uitrusive in oftering a description of it* 



This apparatus, (Plate IV.) which is of easy construction, 

 and extremely portable, consists of a glass measure M, fig. 1 , 

 graduated into hundred parts; a small gum-elastic bottle, B, 

 fi>i. 2, capable of contammg about twice the quantity of the 

 measure, and furnished with a perforated glass stopper, S, 

 which is well secured in the neck of it by means of waxed 

 thread W'ound tight round it; and a glass tube, T, fig. 3, 

 also graduated, but into tenths of the formed divisions, or 

 into thousand parts of the measure. 



The glass stopper, made fast in the neck of the gum- 

 tlastic bottle, as above mentioned, has its exterior end ground 

 with emerv, exactlv to fi; the mouth of the measure; to ihc 

 lower end of the graduated tubeT, is cemented a small steel 

 cock, which is secured into the neck of a very small gum- 

 elastic bottle by means of waxed thread, SB, fig. 4 : the 

 other end of the tube is conical, so as to present a very small 

 orifice. 



Besides this, the apparatus is furnished with a kind of 

 moveable cistern Cj in which the tube can be slid easily up 

 find down, and vet in such a manner that the water or other 

 liquid in the cistern may not pass. This is easily accom- 

 plished by means of a cork fitted into its mouth with a per- 

 foration through its axis to receive the tube. The cistern, 

 when in use, is to be filled with water or mercury, as the 

 experiment mav require, and becomes a secondary cistern 

 for the measure, as will be niorc clearly understood by the 

 following description of tiie method of performing expcri- 

 )B4t:nts with tliis instrument. 



U4 The 



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