Although a disease which has been recognized for centuries, it is only in recent years that medical science has been brought to bear upon it and the causation fully investigated. The result is that much new knowledge has been brought to light. For practical purposes it may be regarded as due to two main causes : (1) The lack in the food of an essential factor or vitamin, which leads to a condition of the body with diminished resistance to deleterious influences. (2) The addition to the system during this devitalized state of a poison. Prevention aims, therefore, at the provision of food containing the active vitamin in sufficient quantity and in taking steps to eliminate as far as possible poisons from the system. With regard to supplying the vitamin, naturally much of the provisions carried must be in the form of preserved foods. Unfortunately, most canning and preserving processes have a detrimental effect upon the vitamin, and it is under conditions where men are compelled to live on them for long periods, with no access to fresh foods, that the danger of scurvy arises. For many years lime-juice was regarded as a sure preventive and a certain cure, but this has proved fallacious. There are, however, certain canned and dried foods which contain active anti-scorbutic vitamin, though not in such great amount as fresh vegetables. One should endeavour to rely, therefore, not on any one product, but on the regular provision of all foods which are of value in this way. With regard to the dietary, there are two sets of conditions to be prepared for: _Life on the ship or at a well-stocked base_, permitting of a full and varied diet for which more or less bulky foods can be used; and _sledging conditions_, including abnormal circumstances arising from accident, which require a close ration. In making my arrangements I placed reliance on the following foods: For the first set of conditions, lemon-juice concentrated by the method advocated by Surgeon Rear-Admiral Sir P. W. Bassett-Smith; dried milk made by the “roller” process, condensed milk prepared by evaporation in vacuo; canned tomatoes; peas, beans and lentils for being made to germinate, and on prolonging the use of potatoes, carrots and onions as far as conditions should permit. Under sledging conditions the party is placed on a definite limited allowance. A sledging ration is composed somewhat as follows: Pemmican, nut food, biscuit, tea, sugar and dried or condensed milk, amounting to a total weight of about 2½ lbs. per man per day, and having a food value of about 5,000 calories. Of these, only the milk can be said to contain active vitamin, and not in sufficient quantity to prevent scurvy. Shackleton added to his _Endurance_ sledging ration capsules of lime-juice prepared without heat. This was in 1913 when the vitamin theory was scarcely evolved, and is an example of his remarkable ability to organize in detail.