On carefully analysing the preceding remarks on food and some of its uses after it has been digested, and the composition and properties of the gastric juice, it is obvious that salt is not only a simple adjunct to food, and therefore not of much importance, but is an article of diet in every sense of the word, and as necessary, if not more so, than many aliments which are regarded as essential. In its relations to animal or nitrogenous, and vegetable or non-nitrogenous, food, salt is in every respect important. The hydrochloric acid of the gastric juice, which is so bountifully secreted by the glands of the stomach, of course drains the whole system of its salt, and especially does it draw the chloride of sodium from the blood, which contains 3·6 in 1000, being held in solution by the liquor-sanguinis. Animal or nitrogenous food contains only a minimum of salt, which chiefly exists in the muscular tissue, its principal constituents being albumen and fibrine; if, therefore, it is eaten as a rule without salt, digestion is by no means facilitated, because meat being comparatively tough, the glands have to secrete an increased quantity in order to break down or disintegrate it, and there is, as I have observed, a greater drain on the system. Vegetable or non-nitrogenous food contains potash; only those vegetables growing near the sea contain soda. The same reasons which apply to animal food hold good as regards vegetable, with this difference: the gluten, the legumen, and their other ingredients are acted upon by the gastric juice more rapidly, and that being the case, a less amount is required, and as a natural consequence less salt, or rather chloride of sodium, is abstracted from the blood; because the more the stomach is called upon to exert itself, a greater flow of blood to that viscus is the result, which takes place only when the food to be acted upon is of a harder or tougher material than ordinary, when the organ is filled to repletion, or when salt is omitted as a rule.