W R REVIEW. [February 15,1910.

REVIEWS. - THE NATUnAL OROAXIC COLOUlUSO BfA’lTERS. Bu

JlOnog~apks A. G. PERKIS U I I ~ A. El. flVElIEST. 011 ZndirslriaZ C k c ~ ~ i isfru, cdllcd bu Srn ELI. THOIWE. Z’p. xxii + C G . (Lo~rdon: Lorigmcar~j, Grcc1l. Ulld co., 191s.) f’ricc 2%. 1lCt.

During the pnst fifty years tlic iiinin trend of organic cliemistry lins been in tlic directloll of tile synthcticnl pre1)nriitio11 of SUbStllllCCs likely to h of use in niediciiic or industry, and tlie grcnt suc- cess wliicli 1111s nttended this 11118 led to ucgicct, of tlic study of nnturnlly o-curring substnnccs and the ~iroccsscs by wlilcli they lire formed.

The living orgrinisni, by nicriiis of react ions occurrin:, ;it tile ordiiinrg temlarnturc, ’‘ ninn1i- factures iniliorlnnt subslnnces, such ns cnrbo- hydrntes, dyes, rillinlolds imd 11roteins, some of which linve, indeed, been synthesiscd in the inborn- tory but only by tlie nid of dr:istlc ccge~iis incom- pntible wit11 the life of nn orgcinisiii. Altiio~lgll tile stntclnent tlint lnniiy of tlicsc iiliturtilly occurring substnnces nre not surprissccl by iiiip of our Inborii- tory products is iiiore npplicnblc to crirboliyilrutes nnd proteins thnii to dyes, Nliturc l ins even in Llie Itittcr cnsc introduced to u’s two r:ilnnblc dyes -nlizurin and indigo-the studs of which greatly facilitnted the ~rogress of certriin portions of the dye industry. W e ~nriy, 1ierlinp8, even m y tlint i t is not improbnble tlint the study of those nntunil dyes the constitutions of wliicli lire ut present unknown mny throw iiew light on tlie rclntions between constitution rind colour nnd tliercfore con- tribute to the progress of the whole dye industry.

3Iuch rescnrcli still rcniaiiis to bc cnrried out in this field which lins n peculltir fnscinntion for nnsonc who likes vririety and difficulty in the groblelns he i1l~estig:lteS. To such 11 chemist we hnve no 1ieHitntioii in recolnmcnding this book ns one thoroughly deservlirg his study. He will find in i t s nineteen clin~itcrs cleiir iincl interesting descriptions of work on s~ibslanccs of tlirJ niosl diverse churnctcr, such 11s riliznrin, ciirinlnic ncid. brurilin, berhrin, cntecliiii, curcuinIn, cllnglc acid, indigo, lnpncliol, !lie fliivoncs, tlie siintlioncs, the tannins niitl tlic tintliocyniiins. IIc will be Indebted to tlic nutliors for plnclng tit 111s disposnl n book which covers pruct icnlly tlic whole scient ific litcni- ture of the group nnd wliicli, Inorcovcr. in sonic plrices coiitiiins tlic results of inrestigntions wliicli tire now piiblislied for the first time.

Notwlthstiinding Llic wide rnngc of tlic book i t is, with the esceplion of some obvious ty1)ogrnplii- cnl niistrikcs, singultirlg free froni errors. The only omisfiion froni if of iiiig iinporti~nce is tlirit of the investignt ions by Liebcrinnnii mid his pupils of the dye nztifriii, \vlitch i s closcly rcliitcd to biixin. Also, in n I J I ~ I I O ~ W J ) ~ ox itidiislrIcrE cRcitifs- tru we should in this ctisc hnve cspectcd 11 cliriptcr (lenliiig in n gencrril iii:iniier with the innnufnc- turn ,pf estni$s of !,yes, deyibing for i~istnnce tlie cutting nnd curing of dye-woods 1111~1 sollie Inodern types of estriiclloii-britlerles. In not iliclrlding such n chiiptcr 111 tliclr book tlie nutliorH llt1l-e, ~wrl inl~s , ndhcred too riaidly to tllc iytr l ic- tlons of tlie gciiernl editor, wli i~l i esClIldC tech- niclil gir~~i i i t icc of mnnufncture ” fro111 111~ ~ o l ~ ~ of these iiionogrnplis.

It is mtisfilctory to flrid the tnnnlns very fulls clcwrim, 1111 tliq,niore Iri;lnce w r e r ~ l l iilnnts, whicll tim still used ns (1ycH in some rcniotc difitrictfi, owe tlleir tinctorin1 l i r o l ~ r t i e s to the tnnnlns. In rlddition to tllc bett cr ~;now~i p o l y - d ~ ~ i i l e ~ descrlbcd ill tile cliliptcr 011 tliu licliens. tlie fiutllors might

lin\*e g l \ ~ i n brief clcscriptioli of work, llowever illlDerfect i t nlliy IW, which lins h e n carried out oll w)me of tilt less well-known lichen con- ntltuents HllCll L ~ H (1ivriric~itIc nnd llsllie WIdR. Tile rlttcntioll of tlic soiingcr CllCllllHtH lllkllt t1 lUR bC

drown to the desirability of investigating the mnny comPoiruds (about one hundred mid sixty) of UU- h l 0 w I l WnStftUtfOn fsolated by Heme, Zopf find others from licliclis, whlcli possibly fulfil f m p o r h n t illiysiologicnl functions in the Cryptognms tile flnvones nnd tlic nntliocynm do in the Phanerognms

~ ~ I O D E I ~ N Comno Piwrrm. ul/ .T. EI. C I ~ I ~ T O P I I E I I .

HUCIII RYAN.

ItIClItditig tho AtiUlUsis of dlutcrials ufl<l l ~ r o - drtcts, I ~ u T. H. BPI(O.\t. S C C O ~ I ~ edition, in two voliimcs. (Loticlotr: aroybu Loc/,mood afld

Tile second edition of Alcssrs. Christopher and Dyrom’s work 011 Modern Coking Practice rctriiiis tlie ndvcintnge of conciseness-tile first voluinc now conii~rislug 104 nnd the second 120 pnges of test rind illustrntions, to which must be ridded sonic 2.5 plntes, niostly rci)roductions of views of plnnt. Swnklug broridly it presents n very serviceiible cpilonw of tlie principles rind prnctice of tlie coking of conl for nictnllurgicnl uses, with references to sources of more eshnustivc iiifornintion on piir- tlculnr items.

The first volume embodies descriptions of vnrlous types of conl wrisliing plnnt, vnrieties of coke ovens nnd of tlie inwhnnlcnl npplicinccs used in coiincsion tliercwitli. The descrii)tlons nre good, but only rnrely do tile I i l i t l i O ~ S olkr criticnl obscrvntionR to guldc the render on tlic merits of the dilTerent types of nppnrntns or plnnt. Neither does tne book give liim sufliciently full dntn or informiition to ennblc him to form for himself 11 just 01iinion tlierefrorn on the compnrntive utility of the vnrious types. l’erlinps, when n third edition is cnllcd for, the nutliors will give tlic render the fldVnllklgC of their considered opinion cind espcriencc on these points. The metliods given for the prosirnilbe unnlysis of con1 nrc in mnny instnnces-+.g., the estinintion of nsli nnd volntilc miitter-iiisnmclentlg definite to give coiicqylniit results in tlie linnds of dilTerent nnnlysts. l h i s is especitilly true of the deterininntion of roltitile mntter, \vhicli, beixig nn cnipiriail tcfit a t best, must be cnrried out In 1)rcciscly defined conditions.

The rrecond voluine clcnls with ‘the By-Products of Coking, including tlic principlcs nnd nietliods of their recovery rind tlie tests of qunlity usuiilly npplicd to tlieiii. In Llie chiipters on condcnscrfi nnd cslinusters tlie nutliors follow their iirnctice in the flrst volume of refrnining froni coniprinitive criticisin of tlic dlffcrent forms of plnnt,,describced, but in tin esccllcnt clinpter on “ Direel proccfifm of nmiiioniii recovery there is this useful opinion I I H to the rcltitivy6 iiicrits of direct nnd semi-direct proccsws, viz. : dclinitc ndvnntiigcs peculliir to one rryslcin :ire coiintcrbnlnnccd by cqnnlly definite clisntlvnntngcs, mid so fnr the writer, froin obser- rtitions n t sevenil plnnts of both types, 1s unnblo 10 express tiny preference for citlier type.” I f only the nutliors could hiivc seen tlieir wny to eslircss tlic results of tlieir cspcrlclice cqiinlly esplicit Iy in other clinptcrs. tlicy \vould hnvc ridded i11l111cnscly to the vciliic of their book. Tlic nxirilytl-

lucthode given in the second volume vnrs grcritly in merit, niid iicccssnry preciiutlons nrc often 0111itte(l. For instrincc, in the clctcrmlnntlon of “free cnrlmn ’* in trir, tlie URC of n Soslllet IlpPII- rill 118 is rightly ircoinnienclccl, but tlierc 1s 110 (llrectloll to dry tlie empty thImble before ~~’Ckl l - lIlg, tilollgil tile t l l~i i ib~e nnd contents nrc? (lrled bfore tile nnlli wclgliing. Pmntlicticcills the mviewcr llllly observe tlint in thlH clctcrniinnt 1011 iIe lnvliriribly llHCH n similnrly-1 rented cnii)t.P tllim\Jle ns n couiitcrpoi~c, nnd f l n d R the resultfi obtliine(1 nrc niricIi niow Iierirly concordnnt t h l l wllcn no siicli counterpoiso in uficd. l’llo bonk I1R

lvllole is, liomcvcr, frco from riny w r i o w f n ~ l t R rind errors, nnd is likely to Drove I l N f ~ l .

Soti, 1917.) Prim pcr tioliiti~c 7s. (id. net.

jv. J. A. ~ I J l T E I t Y I E I ~ I ~ .