It is a marked peculiarity of hypochondriasis that it is far more common in men than in women; a relation which is precisely the opposite to that which rules in neuralgia. Hypochondriasis is also pre-eminently a disease of adult middle life; it is scarcely ever seen in youth, except as the result of excessive masturbation acting on a temperament hereditarily predisposed to insanity. The results of treatment frequently assist our diagnosis in difficult cases. Almost any medicine will relieve the pains of the hypochondriac for a time, and it is generally far easier to do him good, temporarily, than it is to relieve a neuralgic patient; but, _en revanche_, every remedy is apt to lose its affect after a little while. The only chance of producing permanent benefit in hypochondriasis is by the judicious combination of remedies that remove symptoms (especially dyspepsia, flatulence, etc.), which mischievously engage the patient's mind, with general tonics, and, above all, which such alterations in the patient's habits of daily life as take him out of himself and compel him to interest himself in the affairs of the world around him. And, after all, our best efforts will frequently lead to nothing but disappointment. It is notoriously the fact that hypochondriasis especially affects the rich and idle classes; but it would be a great mistake to suppose that it never attacks the poor or the hard-worked: only, in the latter instances, it apparently needs, for it development, the existence of strong family tendencies to neurotic disease, and especially to insanity. Among the numerous debilitated persons who attend the out-patient rooms of our hospitals we every now and then encounter as typical a case of hypochondriasis as could be found even among the rich and gloomy old bachelors who haunt some of our London clubs. I have one such patient under my care now, who has been a repeated visitor at the Westminster Hospital during many years: he has had pseudo-neuralgic pains nearly everywhere at different times; but his most complaint has been of pain in the groin and scrotum of the right side. The existence of what seemed, at first, like the tender points of lumbo-abdominal neuralgia, at one time led me to believe it was a case of that affection; but I was soon undeceived by finding that the tenderness did not remain constant to the same points, but shifted about. This man has professed, by turns, to derive benefit from nearly all the drugs in the Pharmacopoeia; but the only remedies that have done him good, for more than a day or two at a time, have been valerian and assafoetida, with the prolonged use of cod-liver oil. He will never be really cured; and I suspect that the secret of his maladies is an inveterate habit of masturbation acting on a nervous system hereditarily predisposed to hypochondriasis.