area grows more quickly in that region than in those adjacent; the cancerous growth appears to be stopped for a time at the invisible edge of the first nerve area to be affected. The fact appears certain, the explanation very difficult. It is of course possible that the cause which stimulates the cancer-cell to undergo its abnormal growth may reach it through the nervous system, but there are difficulties in accepting this view. The work, however, is suggestive.

Lastly, as regards treatment. At present the only curative method of any value is the surgical one; early and complete removal of the tumour where practicable is the only form of treatment which offers any hope of complete cure, except in one or two special forms of the disease, which will be mentioned subsequently. The two great discoveries of the nineteenth century, anesthesia and antiseptic surgery, have revolutionised the treatment of tumours; exploratory operations are now undertaken in all doubtful cases, and portions of the tumour removed for immediate microscopical and other examination. When the disease is diagnosed with certainty much more extensive operations than were formerly deemed possible are undertaken with a light heart, and with the almost definite certainty that no evil results will follow from the operation as such. And, what is perhaps almost equally important, careful anatomical and pathological studies have been made of the development and growth of cancer in the various regions of the body, so that the surgeon now aims at the removal of the tissues in which recurrence is likely to take place, as well as the primary growth. There is a rooted conviction on the part of the lay public that cancer is never curable by surgical operation. Of course this depends on what we mean by cure; however long a patient may live without recurrence after an operation, we can never be certain that if he had lived longer the growth might not have recurred. But it is quite certain that a considerable number of patients live for years after the operation, and die from some entirely unrelated malady. How great a proportion do this it is difficult to say, and the numbers will depend on the skill of the surgeon, the earliness with which the diagnosis is made, the region affected, and the malignancy of the tumour in question. But it must be

confessed that, even under the most favourable circumstances, many recurrences take place; and whilst it is incumbent on us to recommend surgical intervention wherever practical, the remedy is far indeed from being a satisfactory one, and in too many cases the most that can be hoped for from the operation is the lengthening of life and the diminution of suffering.

The two forms of malignant tumour in which cures are obtained, apart from surgical operation, are rodent ulcer and some forms of sarcoma. Rodent ulcer is a form of cancer which usually affects the face and occurs entirely in people in middle or late life. It is readily amenable to surgical removal, and though it often recurs, is usually completely eradicated with proper treatment. But it is curable by the local application of radium. After a few exposures the tumour gradually disappears and leaves an area of apparently normal skin, with little or no scarring. After a few years recurrence may occur, but is easily cured in the same way. The X-rays have a similar action and are equally satisfactory, and surgical operation is now seldom employed, at least for rodent ulcers of the face.

The remarkable effects of these forms of radiation on rodent ulcer led very naturally to high hopes being formed with regard to their use in other forms of cancer. Unfortunately the degree of success has been but very moderate. A few cases of epithelioma of the skin (next to rodent ulcer the least malignant form of the disease) have apparently been treated successfully both with radium and with the X-rays, and cases of recurrence after operation have been markedly benefited, but in the great majority of cases these methods are useless and may even be injurious, and neither would be recommended where surgical treatment is applicable. For other and deeper forms of cancer they are practically useless. This has been one of the severest disappointments that we have yet encountered in the attempts to find a cure for the disease. It seems very remarkable that these rays should have so profound an effect in some forms of the disease and none at all in others, and that the rays which penetrate almost without hindrance through the body should be limited in their curative effect to the outer layer of the skin. The subject deserves, and is of

course receiving, the most careful study; the effect of solutions of the emanations of radium, for example, is being investigated, and it seems probable that their employment may be of some use, as they appear to have a selective influence on cancer-cells. We shall look forward to good work being accomplished by the new Radium Institute before long.

The other example of the successful treatment of a form of malignant growth by non-operative methods is the cure of some forms of sarcoma by means of Coley's fluid. This method is now an old one, but it has not attracted much attention in this country in the past, owing probably to the fact that much of the fluid sold in England was almost or quite inert; but Dr Coley himself has claimed to get good results for many years in America, and a communication which he made recently to the Royal Society of Medicine has focussed attention on the subject again. Its history is an interesting one. It had been noticed that tumours, and especially sarcomata, might undergo partial or complete cure after an attack of erysipelas. After the bacteriology of the latter disease had been worked out, Fehleisen attempted the cure of sarcoma by inoculating living cultures of the coccus which causes erysipelas, and thus causing the latter disease. This was found to give results of some promise, but it was dangerous, as the disease thus caused was not under control. Coley improved on the method by using killed cultures of the organism, which cause severe febrile symptoms, but which do not set up any progressive disease. He afterwards added a second organism which has the power of increasing the action of the first, and thus produced a fluid which is extremely toxic; a quarter of a drop or less injected under the skin causes a rapid rise of temperature, a feeling of general malaise, and often a shivering fit. The treatment is not a pleasant one, and it is too often useless, but there is no doubt whatever that in some cases it has been entirely successful, and that an undoubted malignant tumour has been completely, and apparently permanently, removed.

The tumours of the classes in which these two remedial agents-radium, etc., and Coley's fluid-are of value form, unfortunately, but a very small proportion of all malignant growths, and we describe them and lay stress on

them mainly since they prove that the problem is not in its very nature insoluble, and that a cure for cancer, apart from the use of the knife, is certainly possible.

A few of the other non-operative methods that have been tried and discarded may be mentioned. Much interest was attracted a few years ago to some papers by the well-known French surgeon, Doyen, in which he claimed to prove that the cause of cancer is a microorganism (which he termed the Micrococcus neoformans) which is very readily demonstrable and cultivable. We may say at once that all claims of this nature are met with absolute incredulity on the part of pathologists. The structure and the bacteriology of cancer have been studied so carefully that it is impossible that an organism such as the Micrococcus neoformans can have been overlooked if it is really present in all cases of cancer. The truth seems to be that the germ in question is one that is very common in the skin and in the air, and that it readily gains access to ulcerated cancers or to those that are in proximity to the skin, alimentary canal, etc. Doyen prepared a vaccine which he considered to be efficacious against this organism, and claimed to get very favourable results as regards the amelioration of the symptoms and the retardation of the rapidity of the growth. His claims were investigated by a committee of the Société de Chirurgie, who reported absolutely unfavourably to the use of the vaccine. At the same time, it appears probable that cases in which there is much inflammation due to this organism in the neighbourhood of the tumour may be benefited temporarily by the use of this vaccine. It may be pointed out that nothing is more difficult than to estimate the real value of any palliative method of treatment. Tumours differ enormously in their rapidity of growth, and sometimes even cease to grow at all; and a considerable number of examples of the spontaneous cure of cancer are on record. If a remedy should happen to be applied to a patient just as the tumour ceases to grow or grows more slowly, the practitioner will naturally attribute the improvement to his remedy. Again, with regard to the improvement in the general condition which is often an apparently definite result of some of the newly introduced methods of treatment, here faith often plays a part of great importance,

and the enthusiastic introducer of a new remedy often claims, quite honestly, to get results that his more critical colleagues are entirely unable to verify. Lastly, it seems probable that a very large number of substances, if injected subcutaneously, cause in certain conditions a marked improvement in nutrition and general health, and many observers have claimed, and we believe with some amount of correctness, to have obtained some temporary improvement after the injection of substances of the most diverse description. This must always be borne in mind in reading of new remedies for which marvellous results are obtained. When a medical man overlooks these facts and happens to meet with one or two cases of apparent success after the use of a new remedy, it behoves him to be most cautious and critical, or he may become a danger to the community.

Another method which seemed to rest on a rational scientific basis was the trypsin or, more correctly, the enzyme treatment suggested by Dr Beard of Edinburgh. It was based on the fact that a structure which is developed during the early stages of the development of the embryo-the trophoblast-has a marked resemblance to malignant tumours whether regarded from a structural or physiological standpoint; the two structures erode the tissues in a strikingly similar manner. The trophoblast is only a temporary structure, and it degenerates and disappears at the time at which the pancreas begins to show signs of functional activity. Now this organ produces ferments which it is at least conceivable might digest and destroy the cells of the trophoblast; hence it seemed reasonable to hope that these ferments might, if injected into patients suffering from cancer, act on the cells of the growth in the same way, causing their death and digestion. This is the theory-a perfectly rational one-which was made the basis of the method of treatment. It met with the few apparent successes which seem to be the lot of so many of the methods of treatment which have been introduced, tried, and quietly laid aside. Unfortunately it was not brought before the profession in a manner calculated to gain their confidence, and it did not at first have the thorough testing it seemed to demand. This, however, has now been done in America by Dr