The carbohydrates are compounds of carbon with hydrogen and oxygen in a certain proportion, e.g. cane-sugar and starch. Mineral matters are inorganic, being chlorides, carbonates or phosphates of calcium, sodium and potassium. Theoretically, any of the three classes of foods mentioned might be thought to supply adequate energy, if taken in sufficient amount. Practically, however, protein and carbohydrate are essential, and it is better to have a mixture of all three. So, in concentrating foods for sledging, the largest possible proportion of fat, compatible with other considerations, is included. Ordinarily, a normal man consumes some four or five pounds weight of solid food per diem, of which 50 per cent., it is rather surprising to learn, is water. When sledging, one has the satisfaction of knowing that all but the smallest quantity of the food dragged is solid nutriment. The water is added when the meals are cooked. It is just in this artificial addition that the sledging ration is not perfect, though as a synthesis it satisfies the demands of dietetics. Food containing water, as cooked meat oozing with its own gravy is a more palatable thing than dried meat-powder to which boiling water has been added. In the same way, a dry, hard biscuit plus liquid is a different thing from a spongy loaf of yeast bread with its high percentage of water. One must reckon with the psychic factor in eating. When sledging, one does not look for food well served as long as the food is hot, nourishing and filling. So the usage of weeks and a wolfish appetite make hoosh a most delicious preparation; but when the days of an enforced ration are over, the desire for appetizing well-served food reasserts itself. The body refuses to be treated merely as an engine. The daily polar sledging ration for one man has been concentrated to a figure just above two pounds in weight, For instance, in recent Antarctic expeditions, Scott, in 1903, used 34.7 ozs., Shackleton in 1908 used 34.82 ozs. and our own amounted to 34.25 ozs. Exclusive of tea, pepper and salt, Shackleton's ration and that adopted by Wild at the Western Base and ourselves in Adelie Land were identical--34 ozs. Reverting to earlier explorers, for the sake of comparisons, McClintock in 1850 brought his minimum down to 42 ozs., Nares in 1875 to 40 ozs., Greely in 1882 to 41.75 ozs., and Abruzzi in 1900 to 43.5 ozs. Our allowance was made up as follows, the relative amounts in the daily sledging ration for one man being stated: plasmon biscuit, 12 ozs.; pemmican, 8 ozs.; butter, 2 ozs.; plasmon chocolate, 2 ozs.; glaxo (dried milk), 5 ozs.; sugar, 4 ozs.; cocoa, 1 oz.; tea,.25 oz. It will be instructive to make a short note on each item.