Before considering in detail the effect of disease upon the nutritional needs of the body, it may be premised that a consideration of experimental work on this subject shows that, on the whole, the energy exchanges of the body follow the same rules in disease as in health. Diseases seldom exercise a direct influence upon the oxidation processes. Magnus Levy, in a paper published in 1906, has ably reviewed this subject. The most marked exceptions to the above statement are found, on the one hand, in myxoedema, in which the respiratory exchange may be reduced to half its normal value, and on the other in exophthalmic goitre, in which the oxidation is increased by 40-80 per cent, a fact which amply explains the wasting so often seen in patients suffering from the latter disease, and indicates that a rich diet should be prescribed. Even in these two cases the effect of the absence or the excess of the thyroid secretion is probably, in part at least, exerted indirectly, through muscular movement. In leuchaemia oxidation is increased, and in fevers, though seldom more than 20 per cent; and in the last stage of exhaustion from any cause the energy exchange is naturally lessened. In diabetes, gout, obesity, syphilis, tuberculosis and cancer the oxidation, in the absence of marked fever, is normal. Alimentary diseases affect the exchange of energy only by causing less food to be taken. Diseases of the heart, lung, kidney, and skin also have no specific effect on metabolism. In all these conditions, therefore, the food requirements will be influenced only indirectly. If a disease enforces rest less food is needed. If, on the other hand, it is accompanied by an increase of muscular action, as in the respiratory movements of dyspnoea or the restlessness of some fevers, this leads to a greater use of energy. Again, when the body suffers a loss of material, as in severe haemorrhage, this requires to be made up. Magnus Levy, in the paper already referred to, points out that we cannot expect drugs or other therapeutic measures to affect metabolism in any subtle way, and must look for the beneficial action of medicines to be brought about by their influence upon the ordinary physiological processes which make up the activities of the body. For instance, by allaying restlessness, improving appetite, conserving the heat of the body or promoting the loss of heat, and so on. The only drug which seems to directly affect the oxidation processes is thyroid extract when given in myxcedema. On normal people its effect is far less marked. Such physical agencies as sunlight, air, cold water all work indirectly through the nervous, muscular and other systems of the body.