CANCER AND DIET.

675 Dr. Yule refers to the " handywoman " difficulty. Not infrequently. he says, unqualified women appear to be the sole attendants at confinements, but when investigation takes place there emerges " the shadowy supervision of a medical practitioner." Dr. Yule has written to the C.M.B. for Scotland for guidance as to what constitutes " direction " on the part of a medical practitioner, but so far no light has been forthcoming. He mentions that the Royal Sanitary Institute and the County Councils’ Association have approached the C.M.B. for England on the same point, and that the English Board are of opinion that " under the direction of means " in the presence and under the direction of " and further, that they (the English Board) intend to take the earliest opportunity of pressing for an amendment of the subsection of the Act dealing with the matter which will remove the words " habitually and for gain "--words which render the subsection futile at present.

specifically the

referred to his investigations and, as growth of tumours, stated that I was in agreement with his views. The second paragraph of the article would seem

general

regards

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Correspondence. "Audi alteram partem."

CANCER AND DIET. To the Editor of THE:LANCET. SIR,-Your leading article under the above title in THE LANCET for last week obviously necessitates a reply from me. Needless to say, no one can regret more than I myself the " flamboyant " and unwarranted statements that appeared in a certain section of the public press in reference to my paper in the Physiological Section at the recent meeting of the British Association. And I specially regret that your criticism of my communication should have been based on unsatisfactory reports. Rationing in this country during the last year of the war was fairly stringent, in the large towns at any rate, this stringency having been specially marked as regards those foodstuffs which, as you state, provide the main part of the fat-soluble vitamin A in a normal dietary. And yet, except as regards tuberculosis, there is, so far as I am aware, little evidence that the public health was adversely affected ; while, as indicated by the RegistrarGeneral’s statistics, the cancer mortality for both

especially in London, was slightly though definitely diminished. In the case of the Central European States to which you allude additional factors came into operation. My own investigation as to the results of a dietary sexes,

deficient in the fat-soluble A factor but sufficient (and this is the important point) in every other respect, while at the same time varied and appetising in character, has now extended over a considerable period,1 and has included an experience of it in my own person lasting for nearly a couple of years. During this time I was necessarily engaged in a certain amount of physical as well as mental work. Yet it was not until the end of that period that I experienced any noticeable ill-effect as the result of the experiment -a skin affection of the palms of both hands which readily cleared up on the addition to my dietary of uncooked vegetable food in the form of salads. And Dr. Wyard2 reporting on our investigation at the Cancer Hospital, which you quote, stated in reference to patients on this dietary that " In no case was any unfavourable change in the general condition of the patient attributable to the diet, and in many

improvement was definite, at least at first." The medical superintendents of several infirmaries in which patients have also been under treatment have reported to the like effect. The suggestion that I have overlooked the literature of the subject, and, more particularly, the work of Prof. J. C. Drummond, is hardly borne out by the fact that in my paper I 1 Copeman, S. M.: Brit. Med. Jour., 1920, ii., 159, Discussion on the Present Position of Vitamines in Clinical 2 Medicine. Wyard, Stanley : THE LANCET, 1922, i., 840.

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to be superfluous in view of the fact that in my paper I stated that the use of the dietary had not been found to exert any specific differential effect on the growth of the tumour, as had originally been hoped might prove to be the case ; and that consequently the cure of cancer was not in question, the methods being at most palliative only. As regards this latter point, it may be noted that Dr. Wyard in the report you quote makes the statement that " general improvement, though slight, was in some instances definite." It may be mentioned that estimates as to probable prolongation of life in any instance have necessarily been based on the opinion of those in medical charge of the patients as the outcome of their general experience of cases in similar condition. As regards the final paragraph, I may perhaps be permitted to state that a few months ago I submitted to a meeting held in the laboratories of the Imperial Cancer Research Fund, under the chairmanship of Dr. Murray the Director, a communication practically identical in terms with my Liverpool address. This meeting, at which Dr. Wyard was also present, afforded opportunity for helpful criticism. The dietary in question has been gradually evolved as the outcome of consultations with Prof. Gowland Hopkins and other bio-chemists ; of experiments on myself, and, with their consent, on other private individuals, and of patients in various public institutions ; as also of a comparative study (not yet completed) of the dietaries and vital statistics of certain " enclosed " and " unenclosed " religious communities in this country and abroad. It is, I think, unnecessary to comment on the assumption with which the article concludes. I am, Sir, yours faithfully, S. MONCKTON COPEMAN. Sept. 24th, 1923. -

PROBABILITY AND EXTRASENSORIAL CHANNELS OF KNOWLEDGE. To the Editor of THE LANCET. SiR,—In his address on Extrasensorial Channels of Knowledge (THE LANCET, Sept. 8th), Prof. Charles Richet brings forward evidence which, in his opinion, establishes the truth of " knowledge of reality obtained by other means than by the ordinary channels of the senses." Some of this evidence is of the following character. A dreams that B, of whose movements he can have no direct means of information, has died, and, in fact, B has died. To the retort of the man in the street that this is a mere coincidence, Prof. Richet replies : " Chance is, indeed, a very convenient god, to which we can always appeal. But why should we introduce these extremely small probabilities into our calculations ? Practically we never come across a probability of 1 to a 100 million, and yet this is the figure at which one must assess the probability of Wingfield having once in the course of his life a single hallucination, and that just the hallucination of his brother being killed at the same moment. Chance will evidently not explain these occurrences." I do not know how it is possible to assess the arithmetical value of the probability in Wingneld’s case, since I ha.ve no knowledge of the frequency or contents of this gentleman’s dreams, save in one instance, but the man in the street would surely rejoin that, far from never coming across probabilities of 1 in 100 millions, he meets them almost every evening. The probability that the dealer at bridge will distribute the 52 cards in any assigned order is measured by a fraction which has more than 60 zeros after the decimal point before we reach a significant figure, it is the reciprocal of the continued product of 52 x 51 x 50, &c. Events, the probability of which is so immensely less than Prof. Richet’s 1 in 100 millions, happen regularly wherever four bridge players are gathered together. Evidently there is something wrong. The philosophy of the