The London, Edinburgh and Dublin philosophical magazine and journal of science . atus ortubes inside the screen;so that the deflexion onthe electrometer scale,when C is connected tothe insulated quadrants,was solely due to the re-moval of the charge inside0. Any effect of gravity,on the motion of thecarriers towards the sidesof the tube, was pre-vented by placing it in avertical position. 11. The gases that wereexamined were the oxy-gen and hydrogen givenoff by electrolysis of di-lute sulphuric acid. Thecell was raised to a tem-perature about 20° abovethe room, at which it couldeasily be kept
The London, Edinburgh and Dublin philosophical magazine and journal of science . atus ortubes inside the screen;so that the deflexion onthe electrometer scale,when C is connected tothe insulated quadrants,was solely due to the re-moval of the charge inside0. Any effect of gravity,on the motion of thecarriers towards the sidesof the tube, was pre-vented by placing it in avertical position. 11. The gases that wereexamined were the oxy-gen and hydrogen givenoff by electrolysis of di-lute sulphuric acid. Thecell was raised to a tem-perature about 20° abovethe room, at which it couldeasily be kept by runningthe current. By meansof an ammeter and varia-ble resistance in the cir-cuit the current could bekept constant. A methodis thus provided of fillingthe cylinder several timeswith a gas having a con-stant electrification When filling thecylinder with the hydro-gen it is best to lead thegas in at the top, andwhen using oxygen at thebottom, in order that the air may be driven out in as short atime as possible, as it is not desirable to run the current for •—. 136 Mr. John S. Townsend on Electrical more than five minutes at a time, when a number of experi-ments have to be performed requiring the same electrificationin each case. The gases were first bubbled through potassium iodide andthen through strong sulphuric acid, so that they should enterthe tube D perfectly dry. The cylinder and tubing con-nected with it were thoroughly dried by heating them witha Bunsen-burner and then blowing dry air through precaution is absolutely necessary as it only requiresa very slight amount of moisture to form a cloud, and thiswould impede the motion of the carriers. 12. A series of experiments of the following type werethen performed. The cylinder was connected to a pair ofquadrants of the electrometer, which were kept to earth whilethe cylinder was being filled and insulated before blowingout the gas, so as to get the readings on the same part of thescale. The tube
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Keywords: ., bookcentury1800, bookdecade1840, booksubjectscience, bookyear1840
