In thus giving the total percentage of ash contained in any food, however, it must not be forgotten that this is but a crude and imperfect method of arriving at a just estimate of the value of that food, so far as its ash percentage is concerned. Although the percentage of mineral matters contained in the various foods is very small, the part they play in the economy is exceedingly important—altogether disproportionate to the relatively small quantity of this matter. It is well known that if we feed animals (or, for that matter, human beings), upon certain foods, lacking in salts, these individuals will ultimately die of “saline starvation”—no matter how much food may have been eaten, or how well proportioned the proteids, fats and carbohydrates. This is an astonishing fact. These mineral elements, contained in organic compound, must not be confused, however, with the same elements in _in_organic form—in which condition they are quite unusable by the system. This is a question, however, into which I do not desire to enter now. It is very necessary, however, to point out and insist upon this fact—that giving the total percentage of ash constitutents or mineral matter, in any given article of food, is of small value to us when attempting to balance a diet, unless we know _in what_ this percentage of mineral matter consists. That is, 1.7 per cent. ash of a given food may be composed of five different mineral elements (in organic form) and the proportion of each would vary largely. It is quite possible, therefore, for there to be a larger percentage of any one mineral element in a certain food, containing a lesser _total_ ash percentage than in one containing a greater ash percentage. That is, supposing there to be two articles of diet, one containing 1.5 per cent. and the other 2 per cent. of ash. The article of food containing the 1.5 per cent. of salts might contain 1 per cent. of potash, while the article containing 2 per cent. of total ash would contain but 5 per cent. of potash. It would be seen from this that an article of food containing less total ash percentage might contain relatively more of a certain element; and if we wish to obtain and supply to the system certain organic salts, it will only be necessary for us to pick out those articles of diet which contain the largest percentage of the required salt, and supply it to the body, as food, for a longer or shorter period. In this manner saline starvation, and the many ills that result indirectly from it, may be avoided. It will be evident from the above, therefore, that any tables, giving the _total_ ash percentage of the various foods are practically valueless, so long as they do not carry the analysis a step further, and tell us in what this total percentage consists. Only in this manner can any definite results be obtained; but it will be evident, at all events, that any of the articles of diet containing such organic salts