00 t ober 25, 1946 Dear Jaoquest f have waited,' hoping that I would hear fr an ym first, but apparently that is not to be. ' I have boen mean-, aotually, to write to you / for the laat few weeks but kept putting It off, hopim that I would hear from you. What prompts me to write at this partfaulm. momint is the faot that I 8aw van Blel yesterday, on hie WEQT to California from primetan. a little about the leoture that he cave et Prinoetm on ths klnetlas of bact;trlal growth, am3 f lcnrJlR you will be pleaaed to ham tlmt he baaed it almost entkely upon pour work. present at tho leoture, aftor it was all over went up to van miel and told him that he thought he had been deliver hg q nEaOnOd10ape"~ (This ls a pun. If you don't got it , let me bow and 1'11 explafn it in my mxt letter.) He told nre, Ae a matter of faat, Linaum Paullng, who ~7as The work hare has been getting on a little more rapidly in the laot few weka than p?erianaly. ?"?e have not nropmmd vory far in identiPging the adaptive 8t~lntlng ar,l;ert. Ye have found that extraaticm in the presence of oitrate apparently give$ nore aative prepiaratione whloh 1% suggeetivo of the possibility that it may be 8 deso~ibose~leio-aoidd-oantaininCp oomponnd ainoe oitrate baotivates descxyribonnoleaae. yet a vory slim lead end, poreonably to m, 8 bit disappointing sinoe it le getting to be rather monotonous to find blolo~kml aativity OOnaQntratt3d in thio fraotian. Om othw thing of intereat. iile have attemptad to test tho thoorg that I pwpoaed at tFo Cold SyrLag mrbor Symgoslum bg trying to adapt a oell to an enzyme whhh it oould not urn4 So far 8~p the thoory le aonaerned, it ahould not make any diffescpnae Whethsr the enzyme was aotually bslre used or not , the onls oritorion being that 8om oorablmt lcn of mayme ad aubstrate take plaoe. ;Je have gotten an apparently oloar-azt &np3wsr in tho oase of maltose adaptation. hs yota know, rnsltose 18 not formented by ;yoat at pH 7.2 and abovee Va found, homver, that the empe omld be formed at that pH. '\Ye ale now iSt!Rcartlgatlng thles more thoroughly, attempti= to find In partio:zlar how mmh substrate was oopdbined with enqme at tho higher pH. This, of oourse, Is a8 Ve have also repeated yw-r experirnonts, mlng yeast, on the effeot ocfp inoreaaing maltose oenaontratirns m t?M rate of adaptat1 zb Exoeyt 'or a difforenas in the rams of the effoctivo aownntratiom, our reeults are quite iaontlual. Ye are trying to exxmine this entire phenomnon fairly aareFully at dii'forent pH88 ln vim 02 the faot that :ye have found that the, opthl oonoentration for nru~lmal fermentat im rats of maltose shifte i-tith pII3 for example, at pH 4.5 it is 1.5,$maltose mereas at pH 6.5 it has ehlfted to 4% malt oseo Zell, eo moh for aotual laboratory do1q;s. 1[ have not a8 yet finishod 'ig review but atill intend to send It to you a8 oouin 88 it le done. Affairs at the University were quite oompliouted polltioally Srhen I roturnad, aad I apsnt a good deal of time trying to straighten thin@ aut here. now in a rolatively satiafaotorg state. Lhx~egrene to acimbhe intoreeta orroe :i.ore Ath us in view of the faot that I need PI lot of genotioally negative strains to test our wtransforming" aubatariae, an3 he haa agreed to oollaborate with our grow un t kis problem They are I have also boon attentptlng to get the -2 I ram going next woe to hshington to attend a hlgh+mered oonferenae vihiah has a vary peoulinr origin. arlhioh inolUde8 BO&, Einstein, Fermi, van Beumsnn, SOhrodinger, and quite a fm others, have deoIded to turn their attention to biolow and they, thsrefow, arranged khls omfemnoe to t!ioh they invited abmt 8iX biologists, including biologists apparently 1s to give a highly oowlensod aoaamt of what is Zoing on ln modern bioloq, 80 88 to bring ow physical oolleaggaea up to date, don't have mQh hopes that *$a muah Of QJ~ Orii;.iu&l nature Will arise frcm tho oonfereme but it should be interesting ln any (3888. major purpoae in aaoagtiw mas to see 80 mqy high-pwerad brains all oolleated in one room and presumab'ly thinkim about the sglm things. Som of the topmost phagsiaists, Beadle, Ihfller, Cori, ~WIf, and abozlt tWO 0th~~. The PUrpOSe Of $he I 4 will mita you the maults of this intomating expri:wnt if aqrthing of fntn?soat corns wt of it. Please romembsr to qlve my re9arda to AnBxlew and Boris should yau Say hello to him for m ala0 and tell hi7* that I have been John Reinec, who ia standing right beaide me him, laboratory. havlw a very good time :rith ~ib. me, also smde regards. I wderstazd that Rrmhet ie at ths Imtftute Im Rngkinea' Tell Boris that I inten8 rnrit1t-g hfm in the near futwe, if not sooner. See you. in P ria next 8~~men"~ I hope. Youre, Sol Splegelnrsn Depm tmont of Bacteriology Vashin$i on lfgivoraity 3t. Lauis, :lo.