This seems a contradiction of another fact demonstrated by statistics, that age increases the frequency of suicide. It is certain that more old men commit suicide than young men, but on careful inquiry into the statistics of the subject, it becomes evident that the chief incentive to suicide does not lie in the cessation of the will to live, but in the difficulties experienced by old people of earning a living, and in the frequent presence of disease in the aged. Deprived of the means of existence, refused the shelter of charitable institutions, old men are apt to fall back upon a rope or the fumes of charcoal. Statistics relating to the suicide of the aged show that the greatest number of victims belong to the poorer classes. The suicide of rich old men is generally prompted by the presence of incurable disease. There is, however, need for much wider inquiry into the subject. It would be interesting, for instance, to obtain more detailed information regarding the motives which urge the old to put an end to themselves. In recent times the suicide of Max von Pettenkofer aroused public attention. After a distinguished scientific career, he resigned his post of Professor at the University of Munich at the age of seventy-six. He went to live a little way outside the town on a property where he devoted himself to gardening and other country pursuits. Although a sufferer from diabetes, his intellect remained unimpaired, but he became a prey to extreme melancholy, owing to the death of some friends to whom he was greatly attached. Moreover, during the latter part of his life he suffered from a septic affection of the neck. This disease, not fatal in itself, was the indirect cause of Pettenkofer’s death, which occurred by suicide at the age of eighty-three. The _post-mortem_ examination[157] showed a fairly well preserved organic system, healthy, with the exception of chronic inflammation of the membranes of the brain and atheroma of the cerebral arteries. The circumstances relating to this particular case of suicide are unusually well known, and yet there are many obscure points about it which are of the highest importance. The chronic meningitis from which the aged scientist suffered conclusively precluded the theory that the motives which led him to commit suicide were prompted by the phenomena of normal life. On the other hand, instances are not wanting of old men of good education and refined surroundings who cling tenaciously to life, even at a much more advanced age than the Munich professor. The instinctive love of life resembles the sexual instinct in a great many women. Just as the love of life goes on increasing when the best of life is past, sexual pleasure is often unfelt by women until their beauty is already faded. Another character common to the love of life and the sexual instinct is that they both persist throughout old age, although they can no longer be satisfied.