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664 theatre and all its works. Despite firm assurance that fortunate or they might avoid treated areas. For several tropical diseases it- is important, to prevent -insect the operationwill be painless, it is’an ordeal for them to bites rather than to prevent chronic infestation. Rebe awake : the grating of -bones frightens them and pellents serve a useful purpose here, and some remarkably they cannot endure the thought of the knife. Since we effective new ones have been found. Dimethyl phthalate cannot separate the man from his disease, Macintosh is one of the most widely used of these." But some pests and Mushin insist that his wishes must be respected ; if are specific in their dislikes so that other substances or he asks for unconsciousness he must have it, unless there mixtures may be used for particular purposes. At first is some definite contr-indication. the obvious method of using repellents was by smearing TESTING CANCER CURES them on the skin. But it has been found that with THE testing of supposed cancer cures looks at first impregnated garments or wide-meshed veils the effect lasts much longer.9 Apart from the Russian experiments sight simpler than it is. No two human tumours behave quoted, a great deal of investigation is going on in this exactly alike in the symptoms they produce or their -rate country and America which will probably be kept secret of growth or spread and killing capacity ; thus in tests on humans no strictly comparable control observations until the end of the Japanese war. Butventually these can be made. Moreover, it is useless to assess results innovations will become generally available for public use, until at least 5 years have gone by. Bold experiments and then we shall have new measures of protection with substances are of course ruled out, poisonous mites. harvest fleas and against mosquitoes, midges, though such experiments made on animals might provide NERVE BLOCK IN THE ARM valuable information. Trial of a remedy on humans is BRACHIAL plexus analgesia is likely to. become popular, only worth while after it has been tested first against for modern technique makes it certain, simple and safe. malignant cells in tissue-culture, with normal cell Time was when the method was an ordeal for patient controls, next against transplanted tumours. and finally and anaesthetist, and there was much wriggling by the against spontaneous tumours in animals. This does parties at opposite ends of the needle. Blame cannot not of course apply when some drug whose pharmacology is already known is to be applied to the relief of cancer be laid at one door, however, for only in the very ill would the surgeon insist on a local anaesthetic ; and symptoms. The remarkable effect of stilboestrol in then, with hand untried and only an airy intuition as to r4lieving the symptoms of prostatic cancer could only the exact location of the brachial plexus, the anesthetist have been demonstrated in man. Further experiments often failed-and little wonder. But there has been a in animals may however yet be necessary to find out change of front : the method is no longer the potion of whether stilboestrol or some allied substance, possibly more poisonous, can produce an actual cure. the very ill; it finds its chief application in the very fit, the robust with strong muscle. In a little volume 10 Every cancer research institute which works systemMacintosh and Mushin show that there is no particular atically comes across substances -capable of killing art about injection of the brachial plexus, and that the malignant cells in culture. Reports on these substances operator needs no mystical nerve-divining qualities seldom appear in print because they are apt to give rise to false hopes One substance of this kind has lately for success. All turns on knowledge of the anatomy, and received wide publicity, especially in America. It is the key to success, as Macintosh and Mushin point out, found in some impurity associated with the yellow is the first rib. The operator must be able to picture that rib accurately in his mind’s eye, and to trace it pigment of penicillin, and, though penicillin itself will not; destroy tumour cells, Cornman1 and M. R. Lewis have with the point of his needle. In simple lucid language they describe how this can be done. Teaching is like demonstrated that this impurity has the property of propaganda-a measure of- over-emphasis is essential. killing them while leaving normal cells alive. Earlier Macintosh and Mushin show themselves good teachers : trials in this country on crude penicillin failed to -reveal the anatomy and the method are made palpably clear, any lethal activity on tumour cells, but this negative result does not throw doubt on the American finding, even for the novice, by an abundance of anatomical " drawings in which every step is Mickey-Moused." The for samples of crude penicillin vary widely. The natureB of the tumour-cell-destroying substance in the American method they present is that described by Patrick in 1940, to which they have added their own improvements. product has yet to be determined, as well as the margin It depends on the saturation by local anaesthetic of the between the lethal dose for tumour cells and the survival area of the first rib where the brachial plexus crosses it. dose for normal ones. Usually for such substances the The first and fundamental step in the operation is margin of discrimination is narrow. Thus a compound accurate localisation of the subclavian artery as it given to a mouse in suitable dosage may cause a tumour crosses the rib. -The older methods relied on transfixing to shrink until it is barely palpable, and sections show the brachial plexus ; as soon as par2esthesiae were a shrunken mass of dead cells and connective tissue ; obtained the injection was made. But such paraesbut if no further treatment is given the apparently dead thesise, as they point out, are felt by only 3 out of 4 tumour comes to life and grows again-yet even one patients-; and the old methods were so disappointing more ctose of the compound under trial will kill the that brachial injection came to be used only occasionally. The margin of discrimination may sometimes’ mouse. be lost because the agent is unevenly distributed through Macintosh and Mushin find that by using a 1% solution the body of the animal. And in the preliminary tests of procaine it is possible to make the limb insensible yet to leave it capable of full motor power ; this has with cell-cultures the normal controls consist of a single great advantages for the operating surgeon-for example, type of cell that happens to live readily in culture; in tendon repair. Surgeons have been reluctant to whereas in the body a vast variety of cells which have employ this method in shocked cases, feeling it- might never been tested are exposed to the agent. Other well add to the shock ; but with appropriately reduced pitfalls inherent in the test have already been discussed in these columns.2 dosage, it seemingly adds nothing to the risk. It is unfortunate that in every character save one However simple the method and however adept the operator, many patients have horror of the operating- malignant and normal cells resemble one another closely. The exceptional property of malignant cells 8. Phillip, C. B., Paul, J. R., Sabin, A. B. War Med. 1944, 6, 27. 9. Monchadski, A. S., Blagoveschenski, D. I., Bregotova, N. G., is autonomous growth. Whether the aim of a supposed Ukhova, A. N. Med. Parasitol. 1943, 12, 56. curative agent is tG kill the malignant cell by selective 10. Local Anæsthesia : Brachial Plexus. R. H. Macintosh, MD, action or to deprive it of some necessary FRCSE, Nuffield professor of anæsthetics, University of Oxford ; poisonous W. W. Mushin, MB, LOND., first assistant in the Nuffield 1. Cornman, I. Science, 1944, 99, 247. department of anæsthetics. (Blackwell Scientific Publications. Pp. 56. 10s. 6d.) 2. Lancet leading article, 1944, i 569. Kennaway, E. L. Ibid, p. 647.