A certain amount of albuminous food is necessary for the repair of the body, which is wasted, even in those who live sedentary lives, by the constant activity and change taking place in the organs; but there is but little doubt that the quantity of flesh foods generally consumed by the well-to-do Englishman, is far in excess of the amount of nitrogenous material required to repair tissue waste and to promote secretion. The exact amount of nitrogenous food necessary to barely support life, or to maintain the body in health with a moderate amount of labour, or on which to do hard labour, such as that performed by a navvy or engineer, has been accurately determined by experiments carried out on a large scale in armies and prisons. Thus a prisoner sentenced to less than seven days' imprisonment without hard labour is fed on I lb. of bread, with two pints of oatmeal gruel made of 2 oz. of oatmeal to the pint. For twenty-one days' imprisonment the bread is increased to 1 1/2 lbs. a day. The amount of nitrogenous material in this diet is only 2 1/2 oz. It is the lowest diet on which life can be maintained compatible with health, but without hard labour. An English soldier on home service receives I lb. of bread and 3/4 lb. of meat, which represents nearly 4 oz. of nitrogenous material. For hard labour the nitrogenous material should be increased to nearly 6 oz., which would be represented by about 1 1/2 lb. of bread and 1 lb. of meat. From these facts the conclusion will, I think, be easily drawn that the ordinary Englishman and Englishwoman of the middle classes, who perform no hard labour, and who live, as a rule, sedentary lives, consume far too much nitrogenous food in the meat, bread, eggs, milk, and fish taken in three square meals a day. In the accounts of centenarians recently collected by Sir George Humphry, it was shown that those who reached advanced old age in good health were those who lived sparingly.