3ls-t March, 1966, Dr. 5, D, Watson, Universite de Geneve, TnstStut de Biologic Moleculaire, Laboratoire de Biophysique et de Biochimie (jlenetique, 24 &u&i Ecole de Medecfne, 1211 Geneve, 4, Suisee, Dear Jim, I enclose some vary rough notes on ycxm manuscrfpt. 3 hdpe you will excuse my not revising them further, but Odile is unfortunateJ.y stfll in hospital land I have been very pressed fur time. S am keeping the original until S hear from you where you want ft sent, pp F. H. CL Crick o In what followrs X shall comment rna3.M~ m wha$ f regard aa factual errors cm omfssfms in the manuscript. This should not be taken to imply that f agree with the remainder of the manu- serfpt - there are quite a nmbep of judgment9 whfsh I belfeve to be SEalse which me not dN.otly matters of fact. For exampl@, Chapter ft page 2, you say T3ir Lawrence Bragg WBS nut used to tellfng people that he could not follow the argument? X think this 9s unfair to Bragg because 31-t 3.8 one of Bragg% charwater- iatics in a colloquium that when he did not understand what ~88 said he wrsuld say 95. This bs ast Ealways the cage with tseniar people but At was very characterTstf6 of Bragg.. Z think the fact that he did not always like the way E pa% sr@ments sb5uJd not be generalised to say that he wa8 slm Lo atate when he could not follow an argument. X also think Zt highly unllkeZ&y that he came only infrequently to tea wag due to anything to do with me. It z3eems to me that this fa just a gtxem on your part, Qn a point of detail, it ia not true that I tw2ce flaaded hfs office with waters since Zn fact hits off?.ce was cm the qqxmite stiie of the lab to the room in wh2ch X worked with water; although 9t Ian true that 1 d3.d twice catme a flood it was not dwe to the mbbsr tubing around a condenser but the rubber tubing round 8 m.wtion . lpWP* Xn a aimi.lar vein9 on the next page yw $mply that ths Fellows of Caius did not enjoy sng company bberea\ase of ny ~a~&, X doubt if YOU have any evidence for this since in my ear&y days at Caius f was a8 quiet 88 tfl mouse. X think ysu me just guess- ing, but af course f my be wmng. However, theaa 81~8 tinor points. The first thing 1 etrongly object ts is the beginning of Chapter 2, when you imply that X acauee Bragg of %tealingn one of my ideas, Thie really dae$ not eorrerjpond to what happened. Bragg had the idea quite independently in 8 aomewh& different form; X merely said that it WEM not a new idea, but J aertatfnlg never accused him of aatually stealing it. X wa9 not at all worried about priority, I was more worried in f'a& that the idea had not been used before, Johnia version is that Bragg wae mainly upset because 3 said X: waould think about Bragg*s idea and tell him whether I thought it was right or wrong, In faot, CM it turned out, it was not completely right p m-Me* My formulation of the problem wsa the more exaot one, although BrarggQ~ was quite 8 @aph%a one,, On further pointe of detail, page 2, Chapter 2, it ia not in fwct true that a German bomb .lall on the Xab at the beginning of the war; in fact the lab W&M oloaed at the beginning of the war and it was then I joined the Admiralty; it was at 8~ later date that a German bomb actually fell on the lab, o Xa the same way, it wae not real.3.y C. P, Snow who had muoh to do with w troubles with the Admira 4 I don3 think the exact story ia of much interest - but it was roughly 88 followst the %irat time I (q pmu%ti *J"C k wns IntervIewed forithe Scientiffo Civil Service by three provin- eial professors they rejected me. The Admiralty, however, were 95 keen to have my services that they arranged for me to have a second interview and it was on this oocasion that C!, P, Snow was head of the interviewfng board, X did not produos & very good impression but they nevertheless deeided ts keep me on+ However I then mada up my mind that 1 wanted ta leave and I approached Massey and through him was introduced to A, V, Kill, who wae in fact the major influenoe in getting &ellanby to give me an N,R,C, studentship, In Chapter 3, page 2, you say ?Uohael, then at seheol* was looked after by hia mother an8 aur#, The nhierH af oour8e really refers to me and not to him, but the sentence is not olear. Chapter 3, page 3; at least one of the reasons for my lack of enthusiasm for palitirts was the faot that Z had'-been, z&&r the war ) a Civil Servant at the Admiralty in Whitehall and had seen something of the inside of goverviment and I formed the opinion that it wae not a very interesting thing unless one was eapeoi- ally informed about what was going on. Xt was %OF this reason that we have nwer had a daily paper since thsn anti I never read The Time@ at breakfast 88 you imply, Your acoount 09 what happened with 330.1 Cc,ehran and the diffraction of the 3ha11x is right hm outlfne, but 3.8 wrong in qxi.te a number of datails, What actuallyhappened was that '3t had a headache that day at lunohtfme at the Eagle and went home instead of going to the laboratory 80 that B would get rid of the head* ache in time for the wine tasting, When Z was sittZng at home in front of the gag fire X got bored and started to work on the prob- lem which T had diacuseed with Coohran that morning4 As flap ae I recall I finfshed all the algebra before I went to the wins Last- ing and your wonderful ~nemlisation about the abaenca of women km3 bring me luck 1 don't think has any foundatPt?n in fact at all, Eor is it mrreat to sjlay that"Bill% equations were mom direct and gave easy numarloal solutions in contrast to TYancfsg mm Ilaborious approach:( The fact is that 333.11~~ der%vations wae much more elegant than mine but the two anmra, apart from the fact that each of us m%de a trivial. slip in sign, wtersr 3.dentfcmL Where Btll had the advantage ovetr me w\aas that he had $ table af Bessel functiona and he should get the oredfit for pointfng out that the Bersssl functionls ware of suoh a shape that thay enabled predfctians to be made from the X-ray diagram, I would have dana thas as soon as I had 8een the Bessel funotiona but I had not had time at the moment when he came into w affiae. I -Uke the phrase **bounded up to CoChran'8 affiee@+ - in fact 1 w8s sftting down when he came into mine, At the end of the chapter you tg%y -5- it was jubitantly dispatched to a crystallographic jourml but it was in fact sent to Rature. A longer paper, of which the three of ua were co-authors, was sent to Acta Crgstwllographica at 8 later date, Ny criticism of this chapter, which is partly finicking details and partly mttera of mm importance, iisr typiosl of what 1 feel about the manuscript as a whole - namely that you haves got the thing right in .~a sort of way, but that it is a Ma- tortion of the facts Zf one IL.oske at it carefully. To corn to Chapter 4 2: cannot now rammber what 1 thought at tha time about the relertive importance of protein8 and BRA but T don't thiak it was quiet0 as clear in my aind ae you make out, However you may recall thIe better than 3 ds. 1 tinPnk X was Zntsre&ed 1x1 DRA but X did not fret under the restriction that if belonged to R'iauri ~43 WUdm3; I was mme concerned at the time that he shouM get on with the lob, Incidentally, is it really true that Rosalind was %flaUrS,c8"8 a-t 85 you imply on page 3 of Chapter 4. I donEt think %n Eng3md one ever usw the term **hSredf8 in the phrase 9Ykurfoe ever hired RcqP, @tnd in any OEUW I wouldn*t be surprised if she wae engaged by Bandall. Altogether X feel that some of the wording in this chapter $s.tia bit too strong - words like @%diotP, Hcantakerous foool** and Qhe situation W~EI thus idiocy" give8 the whole chapter 8 too hysteri- cal feeling for my part. I have very ft;w cements ab Chaptexl tji -6- which is mainly about yourself, but I Seem to recollect, page 6, that Frank Putnm OF mwebody else did the same experiments as you at about the sme time and it would be polite to put in just xa mention of that if this is indeed the CBSB* Poor the eame reason I fired I have very little to s&y about Chapters 7 QF 8. In Chapter 9, page 6, I think you don*t get the position of Stokes quit8 ~AEUL Stokes hsd actually worked out quite indep- endentfy of Coo&m, V&Wand myself the theory of helitml dif- fraction, There i8 no question of saying Stokes@ work is not air-tight, it was just 88 good as OUI%. Howewr, ai3 you knaw, the theory is not enough to prove that 8 given picture representa a helix and that was where the doubt lay. It is certainly true that Maurice or Maurice and Stokes were the first people to realize that DWA ~&&t be a helix. In Chapter 10, an a point of detail, X didn't know that &my was et Cambridge, &though this may well be true - 1 think you should check it, In Chapter 11 your ~aocount of our visit to Oxford 8eem~ to be substantially correct. X had forgotten that thia WEIB the occasion that we isay X~~~E%QU?, but I have no doubt that you n remember'thie better thsn Z da. Chapter 13, page 2, you my not want to put it into your mnascript but the scientific reason that YV~ got the water content wrong wae that you told me there were three or four molecule;rJ of water in the unit cell whereas what Rosy had saild was there three or fou + ol@@ul0s of QJatQr per aagmmetrfo unit. Chapter X6, page 5; Odile has a SMSbll comment w You sag that she was keen to attend the Tropio Night Ball since St warj sponsored by black people, She want8 *o point out that she attended bedsuse she waa asked to do the desor- Y ationa and not because of some ~olour prejudice on her part. Chapter 1.8 - I had completely forgotten that you had told me about Chargaff* results before Chargaff himself came to Cam- bridge and before X talked ta John Griffiths. I think the likely explanatPon is that you did ta21 me but it made, no Smpressioa at the time, Qthertise I am quite csertain X would have remembered it when John Griffiths told me about lzlls calculations, On page 3 you sag that V&ffitha did not go along since for sore months h@ had preferred to scheme where gene copying was based on the alternative formation of co-lpI.ementary 8urfaeestic This may well be true but 1: can only say that he did not IWW say thfa &a me at the time, 4 At the time 1 suggested that like bases would &&xaot each other by stacking one on top of each other ana asting if he cou3.d do the ealaulationa~ I was therefore very surprised when he toId me later in the tea queue one afternoon at the Cavondiah that he did not get an attracMo,n of like with likg but he did &p&&. get that adsnine should go with m and guanins waifh oytosine. It was at th5s point that I said to hlt& that this would immediately -8- @.ve complementary replication. He did not make the remark to me although looking back on it it must be oWious that hes thought of the idea for himself as wall, X did not realise at all at the time the implication of this result was that you should have It1 base ratios although it was vexy stupid of me not to have thought about it. It is true that I doubted the exa&mea$f John Griffith9 arguments and espeolally the magnitude of the effect since I was able to make a rough-':estfmate of that myself usiqg simple electrostatics. As I recall it I first heard of the lsl ratios Pn any way that made anyimpressfon on me when talking to Chargwff in John KendrewQ rooms. I had not remembered St was after dinner, I thought it was %n the afternoon, but that doesn't matter. I certainly haven't the slightest reoolleotfon of men- tioning John Griffith% results to Chargaff, although 5 may well have done so. It $S trU8 t::M I afa not at that time know whfah of the four bases was which, but the fa& is that I aouldn9 remember the names that John GrSffiths had `told me* However it is possible that I mentioned them to Chargaff and have sinoe for- gotten. For the same reason 1 did not forget Chargaff*s results fn the embarrassment of the situatfon; I simply forgot them because the names of the four bases didn't mean anything to me* Incidentally, you have omitted from your account that somewhere about this time I dS*d a week's experimental work trying La prove there waa a force in solution between nucleosfdes to give the adenfne - eyanine - guanine - cytoaine attr-nction but that theea experiments failed BeoauQe the effect, if any, WEEI too small For me to pick up by the technique 1 was using, X still have theBe results in a notebook somehhere. Xnoidentwlly, 1 had a lot of trouble convfnc2ng you that Chargaff's rules with the 103. ratios did aean complementary replication, although eventually you oame round; I think you only really came roud &fYxu? you Esaw BOM@ early accounts of 5. Wyatt's wc)rk, although X am not sure of my recollection of this point. I caWt recall at this tfme whether I ever did discuss with John GriffIthrt the ltl ratioa, as far as I know I '~983 the only person in the world at that tfme who realised that l$l ratios meant complementary replfostion, Chapter 22; S don't think it is true that Bragg ;C'jut &&ptibi 434519 manuaoripta ai3fa43. Wha-i; he aotually did wa8 to ask Max and John to go upstrrira and dfsourss it with him at the same time aa we were talking with Peter downstairs. IncidentaZly, you never mentioned, in discussing Paulfng@a model, that he used an old photograph of Asp$y whIQh had both the A and the 13 dif'frac6ion pattern together, ao that he fn fact solved a stru_ature wh2oh never existed in any real sense at all, I think tfhis is so* but perhaps you should oheck the original paper, There is quite an omZaalon 8oMewhere in thfe 8tory fn that soMetiMe in the 8uMmer before LinuUa MOde?t. car~~out you and X9 or at l8aet 1, had a - 10 * long&h talk with Rosy in the tea queue at the Zoo lab at home conference or other in which 8he firmly maintafned the struoture waa not helical and J: maintained that it wa8 certainly likely %a be helical. and that she rshould scrutinise the evfdance whioh appeared to be againat St very carefully. Chapter 24, page 5g themafn reason you gave at the time for puttfing the phoqhates on the inside was the extraordinary one that the long chaPns of the lysine and argfnine +.P?& tha ,=@a G2.d could then bge&& inwards so that their basic groups w$KLd be agafnst the phosphates. I wag always absolutely unmoved by this argument. At the end of the conversation with you a$ you rightly 8' ,.~ fmpZy 1 aeked you why you did not try buflding model-s with the phosphates on the outsIde, Your reply wag that it would be too mmy, to which I replied, as?r you went up the steps, "then why don't you do it?K X ffnd Izt thfB point a major omfssion In your acoount of the model buildingi Xf you recall, as yau rightly BB~, your first started off by puttfng like basee wSth lfke, Thfs meant that there would be a dyadaxfa parallel to the helical axz!.~v and that the angle between resfdues would be W c::,nd nat 36? You were tempted to bufld model8 with an angle of rotation of UP but you were always unsuoccssful and asked me, just. before you t 3 'i::'ent out to play tenr& 1 whether I would do it, I quickly con- vSnced myself that an angle of I.80 was impossible and 1 built a model for you w4-th an angle of about 36O which looked quits - 11 * reasonable. X alsu had diffioulty at this time in getting aoross to you the impostance of the space group of the A fom which was C 2 arsd which tirefore clearly implied &+.JJ at the side. You (3116 not like this apgumewt at all but in the up shot, aA you know, 3 was right. It was for this rea~son that f was very happy at building a model with ah p*"ih of 36% Chspter 2yr page 2; in. gow aocount of the msnuacripts that we got from the I!LR.C, Coml.ttee you should bring out the point that Rosy stated categorfcally in that manusc!qt that& c X think you will 8ee if we look it up 1 the 8tructu.m wa$ nst helical and Maurice+ who ha + separate contribution, reluctantLg fsllowed her example. 5 think Z-t would be sensible atrgway to try and dig up this manuscript and find exaoli;ly what it oontaine4L Going back to the previous Chapter 2& page 6; at the boWxm VaurJtce*a slow an-r emsrgad as r80tnm This is satually slightly ambiguous. You should make it clear that hs when he said ~~No** he meant mt that we couldWt do it but that he would not mind if we played with MA met-lscules. This doss not come over completely clearly ixr the way you ham writtxx: it. Another otiasfon about this perilsd I think is that you shou3.d make clear why9 although we knew that 3121 ratPus meant comple&ntary rsplf- cation, we did not incosporate it in the model bufldWg, Our reason waa that we decided to redecf anything in the prelstminarg - 12 - model building which we were not completely sure of and we could ylot be completely sure thtat this wad ~1 not dui? to 8ome other reason. It was only after we had decided to put the backbone from the out- side and you had explored the like pairing that the astonishing idea daP,ned on UB I and 1 remember very vividly the particular mo- ment 1 that you might be able to get complementary replication by mnking unlike base pairs an8 having the backbones run in opposite Xrections, It was the day after that that you came in, a8 I recall, having oorrectly put the base pairs together, In other words, I thought that we had realised that we should use Chargaff% rules before you made the baae ptdring and that you then looked far theIll, ahd found them. However, it may be that my aecollection of this is not quite correoL There is one technical detail that you. have missc-ld in Chapter 27, although this is not of great imp ortance and we never publish.ed ft. Thia was that at about 'that time I proved a geometrical theorem so that 1 did not have to build both backbones at once but could- work on one half of the base pair in refining the model, Thia made the work of refinement very much easier. Chapter 27, page 4; you may be right about Bragg seeing the model, but my recollection was that when 'we got thtj structure ha was having 'flu and that Bria How)&s went along to see him and told him that we had got the model and ,%hat he only actually saw - I.3 - 9t a little later, Incidentally, I aas so tired after the three or four da$B so1ia mm?al building, during which, if you recall we tried at least two different variants cpf the model, that on the Saturday evening when we had all finished and I had get the co-ordinants I retired home and went to bad, Chapter 28, page 4; I don*t think !l!~dd came over with several younger Btaff - as I recall it it VVas just Dan Brown, Chapter 29, pages 1 and 2; I think ?J-f you 1cWx up terry WywtWs paper youW find that he did say that 1~1 s&Los sould meant complementary replication, or somethUg of this ad9 although he safd it rather oautiously, I think that if you are goi.ng to mention him you should bring in thfs point to do Nlm justica. Incidentally, %t WEW while you were away %n Paris that we both independently thought of the mechanism of the rotation by ahfft Of the tautomeria hydrogen in the base pair. I thought I .< drafted the sentence whfch began Tt ha3 not escapdi our notice rH and I remember we had to defend it from crNicfsms by Hax or John or someone ltfke that, but 9Lt la a matter uf no importance. Incidentally, one of the bizarre things about our yaper Ps that the editor would not allow us to use ,the fnit;fals DATA and so we constantly refer to "the acid" in our paper although we had originally wfitten DNA. I am not quite sure if this was our first paper or our second paper, but we can emsi3.y check that. YQU 8ay Linus arrived in Cambridge on a r"riday Mght, my recolleotPon was - 14 - that it was Good Friday and fn fact the lab was officially closed on the day that we had our meeting. ReadWg your manus6rip.6; I cannot help remember the lecture which I gave on the subject some years ago, ffrst at Cambridge and tiecrsnd at Oxfor?, to societ5es Wterested Iln the history and philosophy of science, The dPfferencs between nay leczture amI your bock is that my lecture had a lot more intellactuaZ content and nothing like so much gossip* Yours midma 8 good story, especially as Pt gives a rather viv3.d picture of what you to at the time, but what I miss in it ZLn the fntellectuaZ elusion that can be drawn about w LU&. we333 up oon- I don't know whether I should write this up iq$ome foftn or another sEnce ft could be comparatively short, Of course there wa$ some gossfp-i.. in my lecture but only just a little hit to alleviate the scientific azqments. Your book on the other hand, is msinly goss%p': and I thfnk it a pfty in this way that there fa so such of it that At obsoures some of the important conclusions which can be drawn of what we did at the tPme. There are quite a number of fallacies going around about the way we did our work and although your manuscript enables one to see through some of them they are not brought out clearly and refuted aa they mfght be fn a more sober treatment;, I think it would be a good idea if you kmd a glossary of some sort of the people fnvolved, especially aa you have two Maxs, Max Peru% and Max Delbruck, and it would i 15 - help people wha do trot know the Oharacters to fallow through if at the beginning there were a ki,st of the rr?xi.wa ahamsters 'with nhort notes at to who they weme