yct iinidcntilictl organic fiictor prcscnt in codlircr niid ccrtniu otlicr oils.
Quitc rcccntly tlicrc hiis bccii publislicd n furtlicr rcport \vhicli constitutcs n most striking contribution to o:ir hiowlcdgc of rickcts. This is tlic rcport by Miss Chick nnd licr col-Icngiics from thc Listcr Institutc, who wcrc sent iindcr the niispiccs of tlint Institution nncl thc Ncdicnl Rcscnrcli Council t o Vicnnn in 1920, in order to ninkc n closc study of rickcts, which at t l i n t tiinc \ m s rnvnging tlic infnnt population of Ccntrnl Eiiropc. (Mcdical Rcsenrcli Council, Spccial Report, KO. '77, 1023. H.M. Stntioncry Oficc. 'is. Gd.). Oiic of tlic inost striking frntiircs of this rcport is tlic preface writtcn by Profcssor Clciiicns Pirqiict, Dircctor of tlic liintlcrklinik of tlic University o f wlio providcd thc facilitics for the \r-ork arid gnrc raluahlc ossistnncc. T\vo quotntions from his rciiinrks nrc givcn below. "Tlic rcsults of tlic first two ycnrs' work of our British collcngucs sliotvcd iiic no rcnsoii for changing 1113' opi~iion (i.c., tlint rickcts wns an infcctious discnsc, to \vliicIi cliildrcn wcrc protic iis tlic rcsult of dcfcctivc liygicnc, dcfcctivc food, ctc.). Tlic minutc niitl conscicntious obscrrntions cnrricd out by tliciii on n lnrgc nunibcr of intliritlunl ctiscs Icd to no clear conc1usion, but tlic third ycar of tlicir work slicd iicw light upon tlic subject." Aftcr rcvic\ving briefly thc iinturc of tlic crucial cspcrinicnts iuadc and tlicir results Iic :rdds :-" Witli this tlic clinin of critlciicc appcnrs to nic t o bc coiiiplctc tlint niiiiiinl cspcrimcnts ilpoli rickcts spplicnblc also t o liiiili, t h t riclicts is n clisciisc of nutrition, iuitl thnt dcficicncy of f:rt-soliiblc ritamins in diet is nii csscntinl cnusc of tltc tliscasc."
JIiss Chick niitl licr co-\vorl;crs Iii~vc foutitl tlint tlic nctioti of suiiliglit, or otlicr soiirce of short wrvc lcrigtli r;idiation, is cipparciitly not to rcpliicc tlic vitamins, but to eiinblc tlic :iniiiinl orgallisitis to ccononiisc its supply of that substnncc. In otlicr \*or&, nil iiiiililitl will rcquirc IL grcntcr aiiiouiit of tlic orgiiiiic factor or factors prcscnt in cod-lircr oil to protect it ngniiist tlic onset of ricltcts if i t is niaiiitnincd untlcr conditions of bad ligliting.