American chemical journal . it upthrough the mercury by means of a wire. The lower and openend of the tube is now closed under the mercury with the finger,and the part of the tube containing the potassium is heated withthe lamp. After the combustion the tube is allowed to cool. Thegas, which now consists of nitrogen, is transferred back again to theeudiometer, and its volume is determined. To perform this ex-periment successfully, considerable skill in the manipulation ofgases is necessary, and it requires so much time that it is notadapted to the purposes of the lecture table. The same object
American chemical journal . it upthrough the mercury by means of a wire. The lower and openend of the tube is now closed under the mercury with the finger,and the part of the tube containing the potassium is heated withthe lamp. After the combustion the tube is allowed to cool. Thegas, which now consists of nitrogen, is transferred back again to theeudiometer, and its volume is determined. To perform this ex-periment successfully, considerable skill in the manipulation ofgases is necessary, and it requires so much time that it is notadapted to the purposes of the lecture table. The same object may be attained much more easily and rapidlyby means of the simple apparatus shown in the cut. It is basedupon the fact that heated metallic copper combines with all theoxygen of the nitrogen oxides and sets the nitrogen free. Themethod of using the apparatus is very simple, and requires butlittle explanation. A represents a gas burette for measuring thevolumes of the gases. ^ is a gas pipette, which is filled with The connecting tube C is made of hard glass and is 3 diameter, and from 10 to 12 cm. long. It is completely 94 Reiser. filled with granular metallic copper, which has been obtained bythe reduction of the granular oxide in a current of copper is held in place by plugs of asbestos in each end ofthe tube. To decompose the oxides of nitrogen, this tube isheated to a red heat with a Bunsen burner, and to prevent it frombending, a piece of wire gauze is wrapped around the outside andsecured by wires. A measured quantity of nitrous or nitric oxide contained in theburette A is passed over the heated copper by opening the pinch-cock and raising the reservoir tube of the burette. When thereservoir tube is lowered, the gas is drawn back from the now consists of nitrogen, and its volume may be readilydetermined. If nitric oxide has been used, the volume of nitrogenobtained will be exactly one-half the original volume of the gas,while
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Keywords: ., bookcentury1800, bookdecade1870, bookpublisherbalti, bookyear1879
