Mineral salts are freely administered in medicine, both for their local and constitutional effects, for quite other than dietetic purposes. We are familiar with the action of alkalis and acids, with the use of chloride of calcium and citrate of sodium, the former to encourage and the latter to discourage the tendency of blood to coagulate; with the exhibition of phosphorus, iron, hypophosphites, glycerophosphates. We are becoming daily more suspicious of the claims of any of these substances to take their position as constituents of the tissues, however much we may recognise their capacity for stimulating functional activity. We are not convinced that so-called organic preparations of chemical salts have a greater capability for action than the inorganic preparations of the same salts when these latter can be tolerated.

It has been proved, indeed, that at any rate in the case of silver, bromine, and iodine salts their effective capacity is determined by the actual amount of the element contained in them, which is always much less than in the inorganic preparation, and that the only advantageous point associated with their administration is due to this very fact - a less vigorous but less irritating result being provided because of the distinctly diminished content of the elemental substance.

In these latter days, however, we are threatened with a whole deluge of organic preparations of the glycerophosphates, iron, iodine, bromine, etc, mostly with a protein basis obtained from milk, meat, or wheat, and all sorts of claims are made for their superiority, their excellence, and their wonderful recuperative, revivifying, or regenerative properties. We are even compelled to recognise preparations of a much less innocent character with alcohol as their basis, the continued use of which is necessarily potent for evil of a serious nature. After much experimentation with such preparations I am not satisfied that their proprietors have substantiated the claims made for them.

The best that can be said in any case for most of them is that those who have a difficulty in assimilating inorganic preparations have a weaker dose of the drug presented to them, generally in a less disagreeable form, and because of diminished disturbance of the organs of digestion there is at least a chance of a greater quantity of the salt being absorbed. Exceptions may probably at times require to be made in favour of one or other proprietary substance, and if it be not invidious to mention one by name, I have seen the administration of liquid iron somatose followed by the most remarkable improvement in cases of anaemia after complete failure with the most approved preparations.

One claim which is continually being made for those with a milk protein basis is that the casein is metabolised and utilised in much greater quantity than is normally possible. But no evidence has ever been offered in support of this statement, and I am not satisfied that the chemical salt combined with it acts differently to what it would have done in an ordinary pharmaceutical preparation. I am quite certain that such substances lend themselves to unintelligent dosing with potent remedies, and I have seen evidence many times that they are responsible for the inception of neuritis, nasal catarrhs, and many other maladies, which the unfortunate victims rarely ascribe to their proper source. The enormous prevalence of neuritis to-day as compared with even a dozen years ago should make us pause to reflect on such a possible causation.

It is fair to add that these remarks have significance only in connection with preparations which are avowedly manufactured with the addition of chemical salts, and that there exist many meat extracts and dried milk products in which the mineral salts are present in the same organic combination as in meat or milk itself. But even here economy should be practised in the eulogistic language employed by their proprietors, and caution must be exercised in prescribing them in more than dietetic doses with the object of adding to the strength of patients. In the great majority of cases disappointment in this connection is sure to result, because it is not easy to make the body richer in albumin merely by increasing the amount of albumin given.

Perhaps the most important lesson to be learned from calm reflection on the facts mentioned in this chapter is the necessity for constant variation in the diet. The average man excretes some 23 grams of mineral salts daily, quite the half of which he must derive from the food he eats, and it is even judicious of him to depend for the most part on the same source for his supply of chloride of sodium, which constitutes the greater portion of the other half. Now as 70 per cent. of the dietetic mineral salts are scattered over the various food-stuffs of the vegetable kingdom, it is essential that from day to day different sorts of fruits and vegetables containing the necessary salts should be included in the menu, and these should be changed from time to time according to the season of the year. This not only insures a regular supply of all the mineral matter requisite for nutrition, but provides it in such a form that it is easily assimilated and incorporated with the tissues. It is apparently also a matter of great moment that food-stuffs should not suffer too much interference in their preparation for the table, as in this way they are apt to be robbed of many of their valuable qualities. It has been amply demonstrated that continuous deprivation of the organic mineral salts of food is detrimental to the maintenance of good health and directly provocative of disease,