Journal . e filled with ; the burette is attached at s andthe platinum foil heated by the battery. By alternatelyraising B and C the gas is sj-phoned backwards andforwards between the burette and the pear-shaped vessel A,, over the glowing platinum in cc. The marsh gas iscompletely burned (to ascertain this read off the volumeof the gas in the burette, pass the gas through cc and readagain) by 4—6 passages over the platinum, provided alarge excess of oxygen be present. ITie gas is finallytransferred to the burette, the carbon dioxide formed by thecombustion absorbed by caustic potash
Journal . e filled with ; the burette is attached at s andthe platinum foil heated by the battery. By alternatelyraising B and C the gas is sj-phoned backwards andforwards between the burette and the pear-shaped vessel A,, over the glowing platinum in cc. The marsh gas iscompletely burned (to ascertain this read off the volumeof the gas in the burette, pass the gas through cc and readagain) by 4—6 passages over the platinum, provided alarge excess of oxygen be present. ITie gas is finallytransferred to the burette, the carbon dioxide formed by thecombustion absorbed by caustic potash, and, after washing,the volume of the read off as before. One-third of thecontraction represents the percentage of marsh gas. As acheck the residual oxygen may be determined, and knowingthe quantity originally added, the difference gives theamount burned by the marsh gas, from which value thepercentage of marsh gas may be caculated. The secondfigure shows the arrangement used by the author when the. March 31,1888.] THE JOUENAIj OF THE SOCIETY OF OHEMIOAL INDUSTRY. 217 mixture contains above 2 per cent, of Mar»h gas, and thecombustion is effected with air. The pis is then syphoned,afttT the iibsorption of the oxygen and the carbon ,from the ordinary (100 cc.)burette to a second larger(200 cc.) burette, where it is mixed with air and burned,as already described. In cases where the percentages ofcarbon dioxide and of marsh pas are very small the authoremploys a 5U0 ce. burette, having 2) cc. of the scalegraduated to 0-05 of a cc. (To be concluded.)—C. A. K. PATENTS. Improvements relatinij to the Extraction of Aluminium fromSubstances containing the same. C. Netto, Dresden,Germany. Eng. Pat. 4228, March 21, 1887. llrf. A MIXTURE of 100 parts by weight of cryolite with 30 to100 of decrepitated common salt is fused in a covered lire-clay crucible at a red heat, and when completely melted,35 parts of metjillic sodium aie thrust down to the bottomof the pot. The sodi
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectchemist, bookyear1882
