iigninst pnrticlc sixc, in which thc vnrilrtioti of opncity fiictor with pwticlc size has bccn cliruiri:itctl mid, by constriletion the tlistniicc m"'= r Thns I logc 2, -0 ' is . t ~t e ordinate of ir iiew citrre of log, -1, 1 1 fi ~11113, tlte curvc c is n curve of I log, -0 i ngiiinst 11, :iuc~ is treelrt~cl ns such, the ititcriiiedinte stngrs i n the iirpuniriit Iwiiig precidy those of tlir itntiietliiitely preceding scctioti.
It ~houlcl be noted that tlic iiicthod is iiot npplicirlile to prtieles of colloid size, since. iii this ease, beciiuse ot' &o\r.iiiiui motion, the powtlrr cniinot F t t l r out of suspension, and iilso for these sites the siniplr Iirns of geoirietricd optics 110 longer Iiolil. For this rensoti the ciirvc of opncity factor (curve A, Fig. ) is not cotrtitnioiis to the ZPTO of prticlc size iitid also the dcriretl viirve (curve C, Fig. )
SI l;bll\1, 1V.c. UC&eivrd DeFetnLwr 1 I, 1745 .and 25' respeotively. Tltese figures twre obtnirretl . I S IS' rwult of nutncrous dct.erinitintions under virying iicctylctic prcssurcs up to iiboiit 15 utiii. HoriutiO cnrrietl out sericv of tlctcriiiiit~itioiis of tlic Ost\r.dtl coefficient over the teniperuture rtirige 0" to 40".
From the irljove Iirief review, it will be SCCII tliirt no worker, with tlic esccptioil of Horiuti, hirs yublislied the rcsulb of iin uccurirtc comprchensive iiirestigiition of the solubility of :trctyIenc in iirctoiie ovcr thc iioniinl tetiipernture riitigc of 0 ' to 40". Horiuti itsctl highly purifcil ~icctylenc, wltjcli ltirtl Iiceii coiillerisetl with liquid air :rtitI friictioiintcd scvcrnl tinies. Hc took the ittiiiost CI rc to ovoid possible errors t o which SOIIIC of the curlier detc!rlilit;/ttioiis hiitl been siibjcot. Iiis liicusiirettieiits, Iio\.eter, were inndo on n volunic busis iiiitl his results esprcssed in the rorrii of the OstsvnId coefficient of solubility, tliiit is, US the \d1iiirc of ncetyIeiie itiicler the tcst cuiitlitioiis tlissolvctl itt one ~o h n i e of solution. For arty piirticiilnr tc!riilicrtiture this corfficietit is itiriepeilrletit of the prcssiirt!. 111 conscquc!t~cc it gives' iio iiieusiire of tlie \wight of ucctyletic