Carcinoma of the stomach occasionally follows a severe blow upon the epigastrium, iust as an ini'urv to the breast sometimes forms the starting-point of the disease in that organ. It is probable, however, that in both cases the effect of traumatism is to determine the location of the growth rather than actually to produce it, much in the same way that an injury in a tuberculous subject is apt to be followed by a local manifestation of the complaint. There are also a few instances on record in which a cancerous tumour of the stomach was found to contain a pin, a spicule of bone, or some other foreign body that had become embedded in the gastric wall and had given rise to chronic irritation of the tissues.

1 Table 19 indicates that brewers, inn-servants, innkeepers, and commercial travellers are unduly prone to cancer; while the prevalence of the. disease among those exposed to soot and the products of copper-smelting suggests the possible influence of arsenic as a predisposing cause.

- Mason found that defective drainage existed in 25.7 per cent, of the houses where the disease occurred.

The older writers were wont to regard grief and mental trouble as important factors in the production of cancer, but of recent years these and similar views seem to have fallen into disrepute. No practitioner, however, who has had much experience of cancer of the digestive tract can fail to have been struck by its extreme frequency in men who have been subjected to great domestic trouble; and, for our own part, we are so convinced that continued mental worry is a predisposing cause of the disease that we make it a subject of inquiry in every case, and regard its existence as a fact of clinical importance.