A Time to Remember Read online

  Julius von Braun, the Director of the Chemical Institute, was a very different type from Borsche. Also rather a small man, he had a rather round bullet-cropped head, atop a very short neck. He had a rather florid complexion which matched his aggressive manner; rather incongruously he had a rather high-pitched squeaky voice. He was known variously in the laboratory as 'der edle Pole' and 'der Bonze' and his assistants as well as his doctoral students (who described him as 'katzen-freundlich'), were certainly made to toe the line. He could be, and usually was, quite single-minded in his approach. In my time in Frankfurt he had a group of students working on the structure of naphthenic acids which occur in petroleum. I remember in particular one of these students called Gradstein, who seemed to spend most of his waking hours ozonising naphthenic acids down in the departmental cellar where von Braun kept a large ozone generator. One afternoon there was a substantial explosion in the cellar - loud enough to cause considerable alarm even up in my laboratory on the second floor. We promptly rushed downstairs, and pushed open the cellar door; there was a certain amount of smoke about, and the unfortunate Gradstein was lying flat on the floor apparently unconscious (it transpired later that he had merely fainted).

  I and the others were about to go to his aid when von Braun arrived, pushed everyone aside, stepped over the prostrate Gradstein and said ']a, und die Substanz?' There must be many stories about von Braun. I did not have a great deal to do with him myself, nor did my colleagues Blount and Morrison. For one thing, I don't think he really approved of our working with Borsche rather than with him and, for another, I rather blotted my copybook with him quite early on before my German was fluent enough to permit of diplomatic or evasive answers. One day at the beginning of the Wintersemester 1929 he asked me if I would come along to the seminar he ran for his research students. I asked when it was held and he told me it was on Saturday at 8 a.m. I suppose I should really be ashamed of myself, but I am afraid I told him in my very blunt German that I was busy on Saturdays, and that in any case 8 a.m. was far too early for me. Perhaps it is not surprising that our relations thereafter were rather cool. Nevertheless, whatever his faults, von Braun was a brilliant reaction chemist and I learned quite a lot from him during my stay in Frankfurt. With von Braun and Borsche on the organic side, Schwarz in inorganic, Dieterle in pharmaceutical, and, across the road, Bonhoeffer in physical chemistry we had a strong and on the whole harmonious chemical school. It is sad to think that all of them fell foul of, and suffered under, the Nazi regime in later years - not, as far as I know, because of Jewish ancestry, but because they had independent minds.

  I had completed enough experimental work for my doctoral thesis by Easter 1931 and I returned then to Scotland to shake off the after-effects of a severe attack of influenza. I returned to Frankfurt a couple of months later to submit my thesis and take my Dr. phil. nat. examination. The examination was oral and was in three parts: (a) a one-hour oral on organic chemistry, (b) half an hour on physical chemistry and (c) half an hour on mineralogy, the examination in each section being conducted by the appropriate professor in the presence of an umpire - in my case the professor of physics who occupied the time by reading the Frankfurter Zeitung. Although the examination was public, one never had an audience of more than two or three and these were simply men who were intending to take their examination shortly and wanted to see what kind of punishment to expect. There was a curious ritual associated with the Doktorexamen in Frankfurt (and probably elsewhere in Germany) at that time. About a week before the date of the examination one called on each of the examining professors at his home bearing a bunch of flowers for his wife, and had a chat. Although the chat was largely given over to pleasantries with the professor of your main subject - in my case Borsche -the visits to the other professors were much more important. It was accepted that a candidate would probably not be expert over the whole area covered by his subsidiary subjects and so one was expected to indicate those parts in which one was most interested (i.e. knew something) and those in which one was less interested (i.e. knew nothing). This pretty custom was intended to, and usually did, avoid embarrassment to both parties in the examination. As a matter of fact it didn't work out too well for me in physical chemistry. Bonhoeffer had come to Frankfurt - his first full professorship - at about the time that I did; being in any case a rather absent-minded young man, and still rather unaccustomed to examining, he confused what I had described to him a week before as interesting and uninteresting. Accordingly, I had a rough half-hour on pre-dissociation spectra and some other photochemical topics based on a lecture course through which I had usually slept since it was given twice weekly at 5 p.m. in the summer semester after I had been swimming in the Stadtwald since lunchtime. However not too much damage was done since, at the end of the day, my ' Note' for the thesis was ' Ausgezeichnet' and for my oral examination 'Sehr gut'. My other subsidiary, mineralogy, had been chosen by me partly because I had some little acquaintance with the subject from my Glasgow course in geology, and partly because it shared with bacteriology the reputation of being the easiest option in the faculty; bacteriology lectures, however, were given in the hospital located on the other side of the city which made my final choice a simple one.

  In opting for mineralogy I chose better than I knew. It turned out that Nacken, the professor in Frankfurt, was a great admirer of Gregory, the geologist in Glasgow, and seemed to consider any pupil of Gregory as a positive asset to his department. Accordingly Morrison and I were welcomed with open arms and our pathway through the subject was made very easy; Bertie Blount also benefited from this for, although he knew no mineralogy at all, it was assumed that, since he came with me to be interviewed, he too must be a Gregory pupil!

  I was much impressed by the oral examination for the doctorate which, especially in the principal subject, was quite searching. The technique - which was customary and did not apply simply to my case - was to ask a question of the candidate and see whether from his opening reply he really knew something about the topic at issue. If he did, the examiner passed rapidly to another topic; if not, the candidate was subjected to more probing so that his knowledge or lack of it could be ascertained. In this way it was possible to cover a very great amount of ground in the course of an hour and an experienced examiner could find out much more than he could have done by means of written papers. One is often told how students in German universities tended to wander from one university to another during their courses. This may well have been true in some places, but it did not seem to be the case in Frankfurt save in the following special circumstances. It was generally held that, if it became clear to you that you were likely to fail in your examination, the proper thing to do was to transfer to the University of Giessen for your last semester; this was in fact done from time to time by the weaker vessels.

  Looking back now, my recollection is that my life as a student in Frankfurt was a very happy one. No doubt matters were helped by the fact that, having apparently a certain facility for languages, I acquired fluency in German rapidly and so was able to get to know people much better than would otherwise have been possible. The student body was pretty cosmopolitan comprising, as it did, many impoverished young men from Eastern European countries belonging to the old Austro-Hungarian Empire, with a sprinkling of Russians, both emigres and Soviet engineering students, Persians and other Middle Easterners with a few Americans but, as far as I could ascertain, no British students other than ourselves. Frankfurt had taken over the colours and traditions of the German University of Strassburg including its student corporations, although it still retained its designation 'Preussiche Staats-Universitat zu Frankfurt a.M.' So it was that, although duelling was illegal, Frankfurt, in my day, still had several of the old fighting corporations. My friend Morrison had rooms in the same house as one Otto Lochel, president of one of these, the 'Freie Landsmannschaft Franco-Saxonia', and we became quite friendly with him. In due course we were admitted as honorary ' Freie Landsmanner' and used to attend from tim
e to time the weekly Kneipe or club meeting complete with our song books and ribbons all in the orange and silver colours of the Landsmannschaft. These meetings were devoted mainly to singing and beer drinking and were relatively peaceful, although I recall on one occasion there was a row over some girl which led to a sabre duel. Duelling occurred at rather infrequent intervals and was usually the traditional 'Mensur' in which the contestants' sole object was to give one another a few facial scars. I did attend one of these events. It was held at 5 a.m. in the yard of an inn in Sachsenhausen, round which we had a series of scouts posted on the look-out for police. This particular 'Mensur' had been arranged with the Darmstadt branch of the Franco-Saxonia which had sent up two or three of their latest recruits (Fuchse), all of them freshmen at the Technische Hochschule, to swap scars with our recruits. It was a curious performance - almost a ritual - each duel being stopped by the attendant doctor as soon as a suitable face wound had been inflicted. At the end of it all we repaired to the inn and despite the early hour consumed vast quantities of beer before returning to Frankfurt. Nevertheless, contacts such as these with 'Korpstudenten' from the various corporations put me much more in touch with the student body than would otherwise have been possible. Most of the students I knew were right wing in their political stance although few of them were extreme. For the most part they sympathised with the democratic National Party; it was only later as the Weimar Republic finally began to collapse that they moved over mainly to the National Socialist Party. Franco-Saxonia apart, we lived the normal student life. In those days Frankfurt was an attractive city with its spacious west end and its dignified central area within the Anlagen: south towards the river lay the beautiful Altstadt with its Weinstuben which we used to frequent when we were feeling moderately affluent. Alas, all that has gone since the Second World War, and the Frankfurt I knew has been replaced by a rather featureless modern city with hardly any of its old character.

  The period from 1929 to 1931 was an interesting time to be in Germany. It began with the winding up of the Allied occupation - I remember celebrating the departure of the French from Mainz with my student friends - and ended with a financial crisis involving, in Frankfurt at least, a run on the banks. During these two years, even I was aware that the Republic was crumbling, and there was widespread and growing economic distress. It seemed that government neither could nor would do anything and, hand in hand with growing disillusion and cynicism about parliamentary democracy, the extreme parties - National Socialists and Communists - began rapidly to make ground. After a good deal of violence on the streets, the Nazis gained the upper hand, the middle ground of politics fell away, and most of the public, including the student body, gradually moved over to them. This was not because they had any real sympathy for the extreme anti-Semitism of the Nazis; anti-Semitism in a mild form was, and I imagine always had been, widespread in Frankfurt but, alas, none of the men I knew really took the Nazi fulminations seriously. What the happenings during those years taught me was that economic troubles coupled with weak and vacillating government leave the way to totalitarianism wide open; all that is needed to complete the disaster is the appearance of a brilliant demagogue such as Adolf Hitler undoubtedly was. And it could happen in any country.

  When I went to Germany I had no clear ideas about a career except that I wanted to do research in the natural product field, but soon it was time to think about what to do after completing the doctorate. Clearly I wanted to go back to Britain sometime but not necessarily at once. Bertie Blount was of similar mind and we did make an abortive attempt to go to Moscow to work for a spell with Zelinsky; it was probably well for both of us that it failed, for by all accounts life was pretty hard for students in the Soviet Union at that time. Blount had also been pressing me to go to Oxford with him and, since in 1930 Robert Robinson had succeeded W. H. Perkin Jr there, I decided to do so provided I could find the necessary financial support. During my short period in Glasgow in the spring of 1931 (when I did a little work on hesperidin) at the suggestion of Professor T. S. Patterson I applied for an 1851 Exhibition Senior Studentship. Entries for this had to go through one's own university, which then nominated its chosen candidates to go forward for the main competition. I remember well a somewhat discouraging interview with the Registrar of Glasgow University who said he would forward my application but that nothing would come of it since Glasgow hadn't figured in the award list for many years, and, moreover, there was an applicant in another subject who was much senior to me and would be the university's first choice. However, somewhat to my surprise, I was in fact awarded a Senior Studentship and I thereupon made arrangements to join Oriel College and start research with Robert Robinson in September 1931 on the synthesis of anthocyanins (the red and blue colouring matters of flowers). Although by that time I already held the German Dr. phil. nat., it eased the problem of entering a college if one read for a degree; since the D.Phil. course at Oxford had only a research requirement and was unlikely to influence adversely any work I intended to do, I enrolled accordingly and, indeed, took the degree in 1933.

  When I went to Oxford people in my position, i.e. graduates from other universities coming to do advanced work, often found great difficulty in fitting fully into college life, and not a few of those who were my contemporaries never really became part of the colleges which they joined. In Oriel I was much more fortunate, became thoroughly integrated and, indeed, came to be regarded as an 'Oriel man' just as much as those who had come up as undergraduates. This made a great difference to my social life in Oxford and, since, after taking the D.Phil. in 1933, I was made a member of the Oriel Senior Common Room I really saw a lot of college life both of the student and the don. It is perhaps only fair to say that my ready integration into Oriel really rested on sporting ability. When a newcomer came to the college the various clubs used to descend upon him to see if he had any qualities that would be useful to them. Now, it happened that I had played quite a lot of lawn tennis since my schooldays, and, although no champion, I was competent enough to have played tournament and representative tennis. I confessed to the Oriel captain that I had played a little tennis and was promptly asked to go out to the sports ground where the college experts would give me a trial. As it happened, I thrashed the college experts and was immediately accepted as a worthwhile member, a position made secure by my election to the University Lawn Tennis Club in my first term. But whatever the reason, I had three very happy years in Oriel.

  Robert Robinson had come to Oxford just a year before I joined him, but already the Dyson Perrins Laboratory was a hive of activity. He had brought with him a group of research men of various nationalities, some pre- and some postdoctoral, and there was an air of excitement in the laboratories. Robinson himself was at the height of his powers and bubbled over with ideas. I had never met him until I went to join him in September 1931 and I still recall with amusement our first encounter in his office. He was seated at his desk writing, and when I came in he looked up and said ' So you've come to do research?' whereupon I replied simply 'Yes.' 'Well,' he said, 'you know I am interested in anthocyanins and for our synthetic studies we need various omega-hydroxyacetophenone derivatives; now I would like you to make some veratroyl chloride and see if you can convert it with diazomethane to a diazoketone and thence to the hydroxyketone.' He then picked up his pen, evidently finished with me. As I was still standing there he looked up and, seeing my rather puzzled expression, said 'What's the trouble?' 'That doesn't sound much of a problem,' I said, 'what about the research I have to do?' He spluttered a bit. 'What? Who are you?' 'My name is Todd.' 'Good God,' he said, 'I thought you were a Part II undergraduate!' He then started to chat about work and took me off to instal me in a small laboratory for two people adjacent to his own, where, incidentally, he also installed my Frankfurt friend Bertie Blount who was to work in the alkaloid field.

  Blount and I occupied that laboratory for the next three years and, probably because of its proximity to his office and laboratory, we sa
w a lot of Robinson - much more than did most of his collaborators elsewhere in the building. We used to brew tea at about four in the afternoon and on most days Robinson would drop in and join us for a concerted attack on the Times crossword puzzle and a gossip about current chemical interests. It was during one of these 'tea and puzzle' sessions that I made the real breakthrough that opened the way to the synthesis of all the major diglucosidic anthocyanins. When I got to Oxford, one of the main stumbling blocks in efforts to synthesise such flower pigments as, for example, cyanin, pelargonin and malvin, was the total failure that had attended all efforts to make the 2-glucoside of phloroglucinaldehyde. Robinson was thinking up some very roundabout procedures to get out of this difficulty, but it seemed to me that since one could put a benzoyl group directly into the 2-position of phloroglucinaldehyde one ought to be able to put in a glucose residue. So I started in to condense acetobromoglucose with unprotected phloroglucinaldehyde; I tried all sorts of tricks, but I could get nothing but intractable syrups and gums. One day, however, I had a methanolic solution of one such gum in a small conical flask and was concentrating it by dipping it from time to time into a hot water-bath while at the same time having tea and doing the crossword puzzle with Robinson and Blount. The inevitable happened; I dipped the flask in for a little too long so that the solution boiled violently and, probably because it was rather hot, the flask slipped from my fingers and fell into the water-bath. I fished it out and put it over among the dirty glassware which I intended to clean up the following morning; to my astonishment when I came to do this the next day I noticed that the walls of my small flask were covered with crystals. They were indeed crystals of 2-beta-tetra-acetyl-D-glucopyranosyl-phloroglucinaldehyde! Henceforth, with seeding material available, there were no further problems and the way to the anthocyanins was wide open. I don't know what moral, if any, to draw from that story, but at least it explains why, in a later edition of a well-known chemical textbook, it is recorded that the 2-glucoside of phloroglucinaldehyde is best crystallised by diluting its concentrated methanolic solution with a large volume of hot water!