9. I have not found the _loss of teeth_ to affect the duration of human life, so much as might be expected. Edward Drinker, who lived to be 103 years old, lost his teeth thirty years before he died, from drawing the hot smoke of tobacco into his mouth through a short pipe. Dr. Sayre of New-Jersey, to whom I am indebted for several very valuable histories of old persons, mentions one man aged 81, whose teeth began to decay at 16, and another of 90, who lost his teeth, thirty years before he saw him. The gums, by becoming hard, perform, in part, the office of teeth. But may not the gastric juice of the stomach, like the tears and urine, become acrid by age, and thereby supply, by a more dissolving power, the defect of mastication from the loss of teeth? Analogies might easily be adduced from several operations of nature, which go forward in the animal economy, which render this supposition highly probable. 10. I have not observed _baldness_, or _grey hairs_, occurring in early or middle life, to prevent old age. In one of the histories furnished me by Dr. Sayre, I find an account of a man of 81, whose hair began to assume a silver colour when he was but one and twenty years of age. 11. More women live to be old than men, but more men live to be _very_ old, than women. I shall conclude this head by the following remark: Notwithstanding there appears in the human body a certain capacity of long life, which seems to dispose it to preserve its existence in every situation; yet this capacity does not always protect it from premature destruction; for among the old people whom I examined, I scarcely met with one who had not lost brothers or sisters, in early and middle life, and who were born under circumstances equally favourable to longevity with themselves. II. I now come to mention some of the phenomena of the body and mind which occur in old age. 1. There is a great sensibility to _cold_ in all old people. I met with an old woman of 84, who slept constantly under three blankets and a coverlet during the hottest summer months. The servant of prince de Beaufremont, who came from Mount Jura to Paris, at the age of 121, to pay his respects to the first national assembly of France, shivered with cold in the middle of the dog days, when he was not near a good fire. The national assembly directed him to sit with his hat on, in order to defend his head from the cold.