April 20, 1O!B coliunu strips out the low-boiliiig coiiiponcnt from t h refliix rtinning back into tlic bottom of tlic colrmui. Thc result is tlint low-boiling coniponcnts up to n certnin point arc cjcctcd from the top of tho still, ivliilst the high boiling coinpouents nrc rcjcctcd by tlic partial condenser and niirst go oat of the boktonr of the column. Goiernlisct~ion S.-Tii testing coniplcs misturcs of liquids of rcnsonnhly noriiinl belinviour, froin tlic stnndpoint of volntility, by dctennining their boiling-point oiir'vcs in the usu:il \wy, tlic iiiitinl boiling point ot tlic niisturc is nln.nys above tlic boiling point of tlic inost rolatilc purc component, and tbc fiinl boiling point of tlic inisturc is bclo\v the boiling point of tlie lcnst vo1:itilc component, unless tlint compotuent is present in 1i1rgc sinount. Furtlicrniorc, in distilling such a niisturc, tlic initial boiling point of tlic distillntc \rill be lowcr tliiiii the initial boiliug point of the original niisture, nntl if tlie scpsration is good, tlic final boiling point of the distillatc mill bc bclow tlic initial boiling point of tlic residuc, :ind this diffcrcncc in tcinpcrature will be grcnter thc grentcr the diffcrcnce in volntility bctmcn tlic most volatilo and tlie least volntilc componcnts in the origintil inisture. With pcrfcct sepnnition, this diffcrcncc in tcnipernturc will Itnvc n mnsimiim rnluc for any givcn cnsc.
Ceitwdisa~ioi~ Sf .-lt is prncticablc to feed a ooluinn it1 :I continuons still with eitlier vnpour or liquid or nny inistiire of the two. Fceding with licpid tends to ovcrlond tlic column wit11 reflus bcloiv tllc fccd platc, pnrtiml:irly if the liquid is cold. Pceding with vapour over-Jonds tlie coluiun wlicn tlic pcrccntnjic of distillate in tlic fecd is stnnll, but inny be vcry dcsirnblc when tlic permitogc of distillnte in tlic feed is Inrgc.