Besides its function of increasing the absorption of water, it is known that common salt is a powerful adjuvant to the absorption of albuminous substances. Pure water is absorbed very slowly by the bowel wall, but a dilute solution of common salt is rapidly absorbed, and a rectal injection of pure albumin is not absorbed until a little common salt is added, when it is rapidly sucked up by the bowel wall. It is stated that the long-continued use of vegetable foods in Central Africa creates such a painful desire for salt that when the natives are deprived of it for any length of time they begin to show signs of insanity. Whether this be due to the retention of toxic materials is decidedly doubtful, but many hold the belief that common salt is necessary for the excretion of toxic products. During many diseases an excessive elimination of chlorides by the urine is considered to be an excellent prognostic sign, because the toxins are excreted with them, while on the other hand retention of chlorides is one of the most frequent signs of auto-intoxication.

Those who advocate the use of large quantities of added salt declare that it induces a healthier appetite, a stronger digestion, and a much more vigorous physique than in those who only use this condiment sparingly. They are particular, however, not to attribute all the good effects to the chloride of sodium per se, but to it in combination with various salts, such as phosphates, iron, etc. There are those again who deliberately declare, on the flimsiest of evidence certainly, that the causation of cancer is bound up with the consumption of common salt. Probably the truth, as usual, lies somewhere midway, and it may be that there are some who display the irritant effects of common salt on the mucous membranes with great readiness, and these certainly should eschew it in daily food.

The addition of a moderate amount of common salt to the food in health is not only not injurious, but, as the balance of the evidence shows, distinctly beneficial.