Some years afterwards, when he was in Paris, John Adams upbraided him for not taking more exercise; but he replied, “Yes, I walk a league every day in my chamber. I walk quick, and for an hour, so that I go a league; I make a point of religion of it.” This was not a very good substitute for out-of-door exertion. In fact, Franklin’s opinions on the subject of exercise were not wise. The test of exercise was, he thought, the amount of warmth it added to the body, and he inferred, therefore, that walking must be better than riding on horseback, and he even recommended walking up and down stairs. Walking, being monotonous and having very little effect on the trunk and upper portions of the body, is generally admitted to be insufficient for those who require much exercise; while running up and down stairs would now be considered positively injurious. But it is, perhaps, hardly in order to criticise the methods of a man who succeeded in living to be eighty-four and who served the public until the last year of his life. Even when he was at his worst in Paris and unable to walk, his mind was as vigorous as ever, and he looked well. Adams, who was determined to comment on his neglect of exercise, says of him when in his crippled condition, in 1785, “but he is strong and eats freely, so that he will soon have other complaints besides the stone if he continues to live as entirely without exercise as he does at present.” Adams also said that his only chance for life was a sea-voyage. Soon afterwards Franklin was carried in a litter by easy journeys from Paris to the sea-coast, and crossed to Southampton, England, to wait for the vessel that was to take him to Philadelphia. While at Southampton he says,-- “I went at noon to bathe in the Martin salt water hot bath, and floating on my back, fell asleep, and slept near an hour by my watch without sinking or turning! a thing I never did before and should hardly have thought possible. Water is the easiest bed that can be.” It was certainly odd that in his seventy-ninth year and enfeebled by disease he should renew his youthful skill as a swimmer and justify to himself his favorite theory that nakedness and water are not the causes of colds.