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XV. Defcrhptioh and Uje of Ct Guy ton'; Eudiometer-* 

 From Journal de l'Ecole Polytechnique, P. i±. 



C>HEMISTS and Philofophers have long wiflied for an 

 eudiometer capable t>f ihewing exactly the quantity of oxygen 

 gas mixed in any other gas. Berthollet has proved, in his 

 Lectures at the Normal School, that the eudiometer of 

 Scheele, which he juftly conflders as the beft, has (till great 

 defects, as the abforption requires fevcral hours, and as 

 towards the end there is a decompofltion of water, and con- 

 fequently a difengagement of hydrogen gas, which occafions 

 uncertainty refpecting the quantity abforbed. 



This induced me to feek for fume fubftance which in a 

 convenient manner might immediately give a more accurate 

 refult than nitrous gas, hycirogen gas, phofphorus, and a 

 mixture of fulphur and iron, the only fubflanees which, as 

 far as \ know, hive been hitherto employed for that purpofe. 

 Sulphure (fulphuret) of potafh appeared to me fit to be 

 tried under this point of view. . I was well aware that at the 

 ordinary temperature it i ! ie only of a combuftion 



ftill flower and more infepfihle than a moiftened mixture of 

 fulphur and iron ; but I prefumed that, if the temperature 

 were raifed by applying a [mail taper, it would be fufficient 

 to put in action the affinity, and to determine rapidly an ab- 

 forption which would not then he affected by any foreign, 

 caufe. The effect fully anfwe red my expectation ; fo that 

 the queftion then only was to determine the apparatus ne- 

 ceflary to form this new eudiometric inftrument. I though* 

 that an inverfed retort would unite fimplichy, convenience, 

 and every advantage that could be dcfired. The following 

 is a defcription of it. 



AB (Plate V.) is a fmall glafs retort with a long neck, 

 and capable of containing from 12 to 15 centilitres*. One 

 nmfl. be chofen fo mush bent that, when the neck is placed 

 •vertically, the bulb may form in its lower part a cavity conr 



* About ii^ht cubic inches, 



taming 



