The London, Edinburgh and Dublin philosophical magazine and journal of science . 14 lb 18 20Time - Minutes. and 3 of fig. 4 and Curves 2 and 3 of fig. 5 show that thedecay effect is a composite one, indicating the presence ofone substance which decays initially from a maximum value Ionization from Heated Platinum, 185 and of a second substance giving maximum ionization after2 to 6 minutes heating under potential depending uponthe temperature used. At the higher temperature (765° C,fig. 5, and 774° C, fig. 4) this secondary rise of positivecurrents with time is not much, if at all, in evidence.
The London, Edinburgh and Dublin philosophical magazine and journal of science . 14 lb 18 20Time - Minutes. and 3 of fig. 4 and Curves 2 and 3 of fig. 5 show that thedecay effect is a composite one, indicating the presence ofone substance which decays initially from a maximum value Ionization from Heated Platinum, 185 and of a second substance giving maximum ionization after2 to 6 minutes heating under potential depending uponthe temperature used. At the higher temperature (765° C,fig. 5, and 774° C, fig. 4) this secondary rise of positivecurrents with time is not much, if at all, in evidence. Thisis to be expected since with increase of temperature thedecay constant of the second substance changes withtemperature ; the higher the temperature the more rapidthe rise of current to the intermediate maximum. Thissecond maximum would therefore be masked by the rela-tively large initial ionization currents due to the first source Fig. Tint - «v producing ions. An analysis of such curves can be madein a manner similar to that given by Rutherford in his* Radioactive Substances and their Transformations, p. plate taken from the above reference is given in theright hand portion of fig. 4. Such a curve as No. 3, fig. 4,may be analysed into two current-time relations, the firstbeing expressible by V = n^e~^yt and the second by theequation ^•3 — *2 Any attempts at details seems superfluous here, since thedecay constants \b X2, and \3 vary with the course the interpretation to be given figs. 4 and 5 is notthe same as that given in radioactive analysis, since we arepresumably dealing here with two distinct sources of ionsand not with a succession of changes from A to B to C. 186 j Dr. C. Sheard on the Positive VII. Increase of Positive Emission produced by previouslyheating the wire under such conditions as to dischargeNegative Electricity. In a general way the effects due to heating the w
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Keywords: ., bookcentury1800, bookdecade1840, booksubjectscience, bookyear1840
