It has been customary for some time to exclude a number of articles of diet as a matter of routine when taking a course of mineral waters. We have already spoken of fat in this respect, and must mention a number of other articles that have been declared dangerous by different physicians. The most emphatic interdiction, and the one that is most disagreeable to the patients, is the withdrawal of raw fruit; boiled fruit, on the other hand, is recommended or is at least tolerated. We have encountered the interdiction of fruit, for instance, in Kissingen, in Homburg, in Carlsbad, in Marienbad, and in a number of other watering places. The Municipal-Bath Committee in Homburg even went so far as to have the rule that fruits were to be forbidden printed on the labels of their bottles. We find that the same conditions obtain here as in the case of fat.

There are undoubtedly numerous patients who should not eat fruit, for the reason that fruit does not fit into the general dietetic regimen that they should undergo; but before forbidding fruit, one should always have definite reasons in each individual case to render this withdrawal justifiable. It is wrong to forbid fruit simply because the patients are taking a certain kind of mineral water. Theoretically, the two agree beautifully with one another. In the course of some preliminary experiments that we performed when investigating metabolism during reduction cures, we intentionally gave large quantities of fruit to patients who at the same time were drinking abundant quantities of the different mineral waters. It was possible in the course of these investigations, when all conditions were so favorable, to supervise the cases with great accuracy, so that any, even the slightest, disturbance would have become apparent. In the course of these investigations we even went so far as to determine the nitrogen, fat, and in part the mineral salts of the dried faeces. Although we gave so much Kissingen Rakoczy and Bitter water that thin watery evacuations occurred within a few hours, we never saw the slightest deleterious influence upon the digestive processes and the general health of the patient from the use of abundant quantities of raw fruit within a few hours after the water was taken.

Since that time we have administered abundant quantities of raw fruit together with the water in a systematic and definite way in cases undergoing reduction cures, and in sufferers from chronic constipation, certain heart lesions, and nervous dyspepsia. As this regulation was given only in suitable cases, we have never seen any unfavorable results. On the contrary, we have come to the conclusion that it is well not only to permit the patients the luxury of fruit, that they can ill miss, but that they are actually helped considerably by the use of fruit.

The same applies to the use of green salads and to vinegar. As a rule, citric acid is substituted for the latter, but we consider it very uncertain which of the two is more deleterious; in fact, as von Noorden has demonstrated in his recent dissertation on the treatment of acute inflammation of the kidneys, and on contracted kidney, citric acid is probably more harmful than acetic acid. Not a trace of the acetic acid taken by mouth appears in the urine, whereas a certain portion of the citric acid escapes oxidation in the blood and tissues, and appears in the urine. Basing on this finding, we have permitted suitable cases, contrary to the ordinary regulation, to eat salad with vinegar, and have never seen the slightest deleterious effect from this practice.

Similar statements could be made in regard to numerous other articles of food and drink, but we would merely be repeating ourselves, for the same can be said in regard to all of these articles, that the drinking of the particular mineral water per se does not call for the exclusion of any article of diet; only the disease itself might justify us in excluding this, that, or the other article of food. If this idea is carried out, and if the quality and the quantity of the food are regulated exclusively according to the conditions existing in each individual case, then the therapeutic application of the mineral waters becomes much broader, and the indications for their use much more general than if one attempts to adhere to the particular kind of diet that is popular in each watering place.

The following is a summary of our most important conclusions :

1. Investigations in regard to the effect of mineral waters on metabolic processes should, if possible, be performed in subjects who are sick.

2. In numerous cases of gastric disorder, particularly in gastric catarrh, the use of saline mineral waters leads to an active and permanent increase in the production of hydrochloric acid.

3. In numerous cases of gastric disorder accompanied by hyperacidity (particularly in nervous dyspepsia) the moderate use of saline mineral waters leads to a decrease of the hydrochloric acid production and a decrease of the subjective symptoms.

4. The administration of saline mineral waters does not call for any particular diet. To adhere to such dietetic schemes as the ones arranged in the different watering places is an antiquated procedure, and one that must be considered a dogmatic method of treatment that may be deleterious to the patient. There is, above all, no reason why large quantities of fat should not be given in suitable cases to patients who are drinking certain mineral waters. Nor is there any urgent reason for forbidding the use of raw fruits, vinegar, salads, etc., in specified cases.

5. The ingestion of large quantities of saline mineral waters does not interfere with the absorption of the food; in particular, the absorption of the fats; this is demonstrated by numerous investigations on patients.

6. The metabolism of the proteids is not increased by saline mineral waters, so that these waters can be employed even in those cases in which it is important to maintain the albumin content of the body, that is, in patients undergoing a reduction cure.

7. The excretion of uric acid is slightly increased when dilute saline mineral waters are taken. This increase in the uric acid excretion is sufficiently marked to justify the use of such waters in the treatment of uric acid retention.