to the dyspepsia, whereas the real fact was that the "dyspepsia" and loss of weight were both results of a chronic deficiency in food. It is evident that some care about food quantities must be taken by all those who do not live on natural foods. For physiologists there is no difficulty in settling the question of quantity in accordance with the signs of the physiology of a normal body. That all, even physiologists, may run into danger if, while living on unnatural or partly unnatural foods, or while making any change of food, they do not consider the question of quantity with sufficient care. That the question of nutrition should be considered in relation to _every illness_ even though it may appear on the surface to have no direct connection with foods or quantities. As a matter of fact, the nature of the food and its quantity controls all the phenomena of life. Some twenty years ago most people lived fairly close to the old physiological quantities, now they have been cut adrift from these and completely unsettled and are floundering out of their depth. A most unsatisfactory, even dangerous, condition of affairs. For the public it will now probably suffice if they insist on raising the question of quantity whenever they suffer in any way. If they are unable to answer the question themselves let them go to a trained physiologist who can do so, and not to a diet quack. But muscular strength, endurance, mental and bodily energy, skin circulation, temperature and blood colour are all things which the public can see for themselves and from which they should in all cases be able to get sufficient warning to save them from the worst forms of disaster. Some people imagine that they eat very little, when as a matter of fact they have good healthy appetites. Others again think they are eating a great deal, when as a matter of fact they take very little. In both cases a physiological test of the excreta will give accurate information. I once had a medical patient who imagined that he produced great amounts of force and performed feats of endurance on wonderfully small quantities of food. His excreta showed, however, that he was merely under-estimating the food he took. A fat man may seem to be living on very little, but fat does not require to be fed, and his real bone and muscle weight is not large. A thin man may seem to require a large quantity of food, but he is really very heavy in bone and muscle, the tissues that have to be nourished. In all these ways appearances are apt to be deceptive for those who are ignorant of science and who do not go down to the root of the matter. It is not necessary to follow the given quantity of grains per pound slavishly and without regard to consequences. It is necessary to see that the required physiological results are obtained.