. American chemical journal . Hempelburette. On the inlet tube a a number of discs,cut from asbestus board and ignited to destroyorganic matter, are placed in order to protectthe cork from the heat. The platinum tube isalso cooled at the points b and c by wrappingwith cloth which is kept wet by means of adripping arrangement placed above. The tubesA and B are filled with air from the outside ofthe laboratory, closed at d, and connected at ewith the gas burette, which was previously fullof water. The flame is applied at/. When theair within the tubes has attained its maximumexpansion, the level
. American chemical journal . Hempelburette. On the inlet tube a a number of discs,cut from asbestus board and ignited to destroyorganic matter, are placed in order to protectthe cork from the heat. The platinum tube isalso cooled at the points b and c by wrappingwith cloth which is kept wet by means of adripping arrangement placed above. The tubesA and B are filled with air from the outside ofthe laboratory, closed at d, and connected at ewith the gas burette, which was previously fullof water. The flame is applied at/. When theair within the tubes has attained its maximumexpansion, the level of the water in g is adjusted according to thepressure which it is desired to maintain in the apparatus. At theend of each ten minute period of heating the tube is allowed tocool down, in order to facilitate the mixing of the portions of thegas in A, B and C Finally a small glass tube, filled with waterand dipping under water in a beaker, is attached at d; the gaswithdrawn by lowering g, and analysed by the method of Supposed Dissociation of Zinc Oxide. 151 The substances looked for, and determined when found, werecarbon dioxide, oxygen, carbon monoxide, hydrogen, and quantity of carbon dioxide found was not in any case inexcess of the quantity normally contained in the air, and was, ofcourse, hardly measurable in the ordinary Hempel burette. Car-bon monoxide was not found at all. The hydrogen was deter-mined by absorption in palladium sponge, the tube containing ithaving first been filled with pure nitrogen. The fact that the airdid not perceptibly diminish in volume when treated with causticpotassa to withdraw carbon dioxide, proves that no oxides ofnitrogen were formed during the heating. Great care was takenin all cases to use only an oxidising flame, and not to allowthe internal cone containing the unburned gases to come in con-tact with the platinum tube. The results obtained are stated inTable I. The percentages of oxygen given represent the propor
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