It is now conceded on all sides that at least 75 per centum of the cases of tabes are directly due to syphilis. Indeed this affection and paresis are sometimes spoken of as parasyphilitic affections. Unfortunately the ordinary treatment for syphilitic manifestations does not affect them in the least. So far as we know at the present time, there is nothing that will hinder the course or prevent the progress or alleviate the symptoms or have any curative action on either of these dreadful diseases. They are much more common in Europe than they are in this country, but have been seen here with quite sufficient frequency in recent years to make physicians, at least, realise the necessity for having young men appreciate the dangers they invite in thoughtlessly yielding to the temptations of great city life. There are other affections which can be traced directly to the social diseases. One of the most important of these consists of certain brain tumours which may even cause death if not properly treated. These syphilitic brain tumours frequently cause paralysis and may lead to permanent changes in the nervous system with consequent loss of motor power. Whenever the symptoms of brain tumour occur, careful inquiry is made as to the previous existence of syphilis in the case, in order to determine, if possible, if this is the morbid agent at work. If there is a history of syphilis it is usually said to be fortunate, for brain tumours due to syphilis may be made to disappear by the proper use of mercury and the iodides. If the treatment of the case is delayed, however, alterations in the nerve substance take place which can not be improved. This disease affects especially the blood vessels and, as a consequence of the thickening of the coats of the arteries, blood may be shut off from certain portions of the brain entirely. This will, of course, produce symptoms of paralysis. Indeed, whenever paralytic symptoms manifest themselves under forty years of age, the physician's first thought is sure to be that there is syphilis in the case. This is not always {323} true, for by heredity and very hard work occasionally arteries become so degenerate that they rupture before a patient has reached many years beyond forty, but the case is always suspicious. In this, as in the corresponding instance of brain tumour, treatment, if applied sufficiently early, may not only give relief of all the symptoms, but produce a complete cure. That is, at least the symptoms are relieved for the time, though there may be relapses. Usually these relapses are quite amenable to treatment, but sometimes they get beyond the control of the physician and death ensues. It is almost the rule where there have been serious nervous symptoms once, that recurrences of them must be feared, and they will eventually shorten the patient's life.