npplied directly to t,lte flnsk. TIN estrnct is dissolved in 15 i d . prepnred is .tlcterniined by iucnsiiring tlle opticnl rotcltioli ns of hot cnrboii tetrncliloridc nnd the solvent ngnin renioved in n tlescri1)ed. siniilnr tniiuiier. The procedure isqiciited with iinotlier 10--15-1111.
Bole U.-Thc sctturntcd solution of rotenone in nlcollol is prepnred portion of liot cnrbou tetrncliloridc. If su11i11 qunntitics of insoluble by dissolriug 1 -2.1'1 g. of 1)lIre rotctiotlc it1 nlisoiutc nleotiol nnd nintcrinl nre present, the purification proccdiue described Inter !rill ninking iip to loo0 ~n l . n t 0". eIiniiiiiitc thcm. IIowerer, if nn npprccinbte quniit.ity of iisoIub1c ole C.-The ctiloroforln, carboil tetrncttIoride, artrl ~)ciizet~o used residue reuinius \vhen the estrnct is dissolved in tlie first portion iu t.lh detcrmiiiiitioti itre nll of " BllnIalt " qunIity. of cnrboii tetrncldoride, it should be filtered oB nnd tliorouglily ~i-aslicd witli fitrtlicr portions of hot solvcut, nfter which tlic filtered Spccinl tliniiks nrc due to the Adviser 011 Agricrtlttire. Straits solutioii plus wiishiitgs slioultl be treated ns directed previously for Scttlctneuts niid *Fcdcriitcd JIalny Stntcs, for supplying correctlyt,ho reiiiovnl of cliloroforni. 25 tnl. of cnrboii tctriicliloridc sntiiriitetl iinnictl ~~i n i p l ~s of the roots of tlic diBercut specics niid rnccs of with rotenone (see vote A) nrc added iiiitl the ~vliole is gcntiy Iientcd dcrris esiiuiiiicd ; nut1 to the Coolm Teelinicnl Burciiri, Dcrkhiiin- under n rrflus coutlctiscr to cBcct tlissolutioii. The ftiisk is cooled stcd, for vnlunble nssistnncc iu grindiup", niisiiig, nnil .pnct;ing tho in on ice-htlt for severnl iniuutes :tiid tlien seeded with u few snuiples 11s required for csnuiinntion. crystnls of rotcuouc-cnrbon tetrncltloritle coniples, if ucccssnry. Drs. Jlurtin nnd I-Inrpcr nre inclel)tcd to the BIinistry of i\gricitlturo Tile fliisk is stoppered niitl swirlctl utitil crysfnllisiition is rippnrcntly niid the Co1oiii:il I~crclopiiicnt Futttl for grntits xr1rit:lt itiade couiplete. If nt this strige only n siiinll qunntity of crptnlliuo mnterinl scpnriitcs, 1-00 p i n of pnre rotcnoiic (scc Bote A) sliould be ntltletl.. Tlie coutcnts of the finsk tire t l m \r:iniictl to clYect conipletc dissolutiou nnd crystnllisiition is iigiiiii iiitluced. The flnsks contuiuing the estrnct niid tile wnsliing solutioii lire plnced 1 S e s t iuornitg (hftcr n niiuinnnn pcriod of I6 hours) the crystnls of eoniplcs nre filtered by suction iu n \veiglicd Jcun gliiss crucible, Gooeli type, higti forin, frittctl, litter tlisc, ~o . I 03 (or uritisli-ninttc cquirntcnt). ~l i e itask nn(1 crystals iire rnpit~ly wnstietl witlt 10-15 nit. of icecold cnrbon tettiieltloritle (siiturntcd with rotenone ns dcseri1)cd in Note A). This tnkes plncc' iu tho opcu liiborntory, tlic iippirrntus and solutions, Iioaever, Iinviiig previously bcou cooled t o 0". Tlie crucilile is nllo\retl to reniniu uuder suction for nboiit 5 ttiitiutos and tlicn dried nt 40" for 1 hour. co-operntion iu tliese inrestigntioiis possible. . Iniperiiil Institute (If. IC. Cooinber) I~otliniiisted ICsperinientnl Stiition (.T. T. Jlnrtin, S. 11. Hnrper) I I C C ~I W ~I N I I ~ ?a, ioi? . iu 1111 ice-bnth niiiiiit:iiiicd tit n tcinpernture of 0 ' overniglit. UNIVERSAL APPARATUSFOR MICRO* OR SEMI-MICRO-DETERMINATION OF CAR*(" AND HYDRO= By C. INCRAM Tho conibiistion nppnrnttis clcscrihcl by tlio niitlior in 10301 lins now beel, illl,~rorcl~ c o l l s i ~c r ~l ~~y . G~~ llcnting llns bcoIl yllpcrsel~c~ by elcctricnl Iienting, 11 new typo or.niniioniotcr IIIIY ~iccn derimd, nnd n special filling. consisting of lend nnd ceriiiiii asides niid d v e r anlts, is used aliicli nbsorbs qunntitntircly Iinlogciis, siilpliiir, niid nrsciiic,iiiitl ciinbles coinbus-Uy titiliving tiiicro-UI~niier nbmrption tubes, inicro-or semi-niicro-snnip~es can be used nccordiiig to tIio ~i~nouiit of sitbstnrlco nvniInIilo nnd typo ofbnlnnco nt Iiniid.