One exciting cause only Ave are certain of, and that is irritation in a A7ariety of forms. Another fact Ave can absolutely proATe is that cancer is at first a local disease, and only later a constitutional malady. Mr. Jonathan Hutchinson insisted on this thirty years ago, and it has been confirmed by modern research, as the following statement by Dr. Bashford will show :

" Our observations on animals show that malignant growths are always local in origin, and of themselves produce no evident constitutional disturbance whatever. These facts are in full accord with accumulated clinical experience in man."

Cancer is undoubtedly auto-infective, hence the danger of an imperfect operation, which, by distributing the cancer cells, implants numerous foci of disease. I recently saw a marked example of such a condition in a patient who consulted me with a view to operation. She gave the history of having had a cancer removed from the breast over three years previously by a radical operation ; at the end of that period a small lump was noticed in the clavicular portion of the pectoral muscle, the skin being healthy and non-adherent. A surgeon removed the muscle, including the lump, but finding enlarged glands at the top of the axilla he attempted to get them away by digital enucleation, with the result that they burst and infected the whole of the wound, which, however, healed by first intention. Within two months every needle puncture was the site of a small cancerous nodule, and numerous other nodules appeared over the chest wall and over the clavicle and shoulder, leading to a rapidly fatal termination. We must all have seen similar cases, and the lesson conveyed is that, if possible, cancerous tumours should be removed without preliminary incision, leaving a wide area of healthy tissue around the growths, and wherever practicable the nearest lymphatic glands and vessels going to them should be removed, whether enlarged or not. If the glands be already infected it is of the utmost importance that they should be taken away cleanly without rupture, and wherever possible in the same piece as the tumour. If for diagnostic purposes the tumour has to be incised, the exploratory incision should be closed by sutures, the skin purified, the knife and needles boiled and the surgeon's hands sterilised before proceeding with the operation. If, unfortunately, the wound has become soiled, it should be irrigated with a large quantity of saline solution or some antiseptic lotion, so as to wash away any loose masses of cancer cells or infective material, which if left will probably become engrafted and grow as in the case that I have mentioned.

My friend Dr. W. J. Mayo, of Rochester, U.S.A., insists on the importance of searing the edges of the stomach wound with the actual cautery after partial gastrectomy, in order to avoid leaving any infected surface after the removal of a gastric cancer; and the importance of that I would strongly emphasise should it be necessary to incise the gastric wall near the growth, though when the incision is made wide of the tumour this is no longer necessary.

Some English surgeons apply absolute phenol for the same reason to any doubtfully infected surface after removal of a cancerous tumour. So long-as the tumour is not ulcerated it is probably not contagious, but from the moment that ulceration occurs transmission to the patient or others, granted a suitable medium, may be possible. Such transmission is, however, probabl}7 rare, as the conditions necessary to a successful transmission must be difficult to realise.

The following facts among- others that could be related seem to prove without doubt the auto-infec-tivity of ulcerated cancer. Williams [firitish Medical Journal, 1887, p. 1369) relates a case of an ulcerating cancer of one thigh infecting the opposite thigh by contact. Cripps reported a case of ulcerating cancer of the breast infecting the skin of the inner side of the arm, where it had come in contact with the growth. Roswell Park, Waldegar, Quincke, myself, and others, have seen cancer to involve the whole length of the trocar puncture after tapping for ascites due to abdominal cancer. I have seen the needle punctures and the adjoining skin, previoush7 healthy, to become infected after the removal of cancer of the ovary, and Sippal has quoted some similar cases. I have seen and others have reported cases of a supra-pubic drainage opening becoming infected after removal of epithelioma of the bladder. Hurry Fenwick has noted its transmission from one surface to another of the bladder, an observation which I can also confirm. I have heard of a case where an epithelioma of a projecting lower lip, which could just touch the tip of the nose in an edentulous old man, gave rise to a similar growth on the tip of the nose, and I have seen a second epithelioma to arise on the upper lip opposite to an epithelioma of the lower lip, and a growth to arise inside the cheek opposite to an epithelioma of the jaw and also opposite to one of the tongue. Schimmelbusch has reported cancerous infection of the lip through the finger-nails of a patient who was handling his cancerous ear.

It would form an interesting subject for inquiry to ascertain how often cancer of the stomach follows on, or accompanies cancer of the oesophagus and cancer of the tongue and mouth owing to the swallowing of cancerous particles. Such cases have been reported by Cornil, Klebs, Lurcke, and Menetrier. That the two are often associated is recognised, but I suspect that the association is more frequent than is generally supposed.

From these observations it seems highly probable that cancer is both contagious and inoculable under certain rare conditions among human beings, as it undoubtedly is among the lower animals.