The dietetic- causes of chronic nephritis, mainly of the interstitial type, and operative only when acting for a considerable time, are as follows:

1. The ingestion of excessive amounts of protein, on account of the catabolic irritants produced. While it is the present fashion to emphasize the next cause and while the older theory of the production of uric acid etc., by suboxidation of protein is denied, the general belief that excessive protein consumption may produce nephritis, is probably correct.

2. A fortiori, the ingestion of large amounts of purin-con-taining foods, especially animal viscera.

3. The ingestion of excessive amounts of salines, on account of osmotic disturbances or direct chemic irritation of the kidneys. The continued use of hard or alkaline or mineral waters comes under the same category.

4. Any dietetic excess in the way of carbohydrates, especially sugars, which increases diuresis continually; or a relative excess in conditions of impaired carbohydrate metabolism, allowing glycosuria.

5. The excessive or insufficient use of water.

6. The use of water in any way impregnated with lead, arsenic etc.

7. The use of foods containing preservatives, such as sulphites, formaldehyd, borax, boric acid, salicylates etc.

8. The use of food auxiliaries which disturb arterial pressure, or irritate the kidneys directly, as tea, coffee, alcohol, spices, etc.

9. The use of vegetables containing- notable amounts of benzoates, oxalates etc.

10. Dietetic causes of all kinds producing gastro-intestinal fermentation or putrefaction or both, especially the latter, and yielding indican and other substances irritating to the kidneys.

The ordinary case of chronic interstitial nephritis progresses very slowly, is nearly free from dropsy and the general health is only moderately impaired. Thus moderate mental and physical exertion is notcontraindicated and the patient requires rather full nutrition.

It is of practical importance to bear in mind that cases of this nature, i. e., those in which there is a chronic lesion but no great disablement, should be restricted in diet as inconspicuously as possible, not only to save the patient discomfort and embarrassment but to avoid the business loss which results from a realization on the part of his associates that he has a physical handicap. A large part of the serious professional, political and financial work of the world is carried on by men with chronic interstitial nephritis and their influence would be diminished or their positions lost if this were generally recognized.

The diet should be largely but not exclusively vegetarian. Jn any one day, we may allow 1000 c.c. of milk, corresponding to about 40 grams of protein and 700 calories, or 6 eggs corresponding to 45 grams of protein and 500 calories, or 200 grams of beef, lamb, fish etc., corresponding to about 40 grams of protein, the calories varying widely according to the amount of fat. Bacon and salt pork containing little lean, may be used up to the tolerance for fat. Obviously the above quantities of milk, eggs and meat, should not be given on the same day, nor is it advisable to give the full amount of any one continuously. On the contrary, it is best to vary the diet from day to day.

The patient should avoid animal viscera, meat soups, broths, teas; vegetables rich in oxalates; condiments; excessive amounts of salt; tea, coffee, chocolate and alcoholics, unless in minimum amount; and considerable quantities of vegetables rich in cellulose and poor in nourishment. Fried foods should be avoided and, in general, all foods found to digest with difficulty or to disagree with the patient. Special pains should be taken to secure fresh, untainted foods of all kinds, particular caution being needed with regard to poultry, fish and shell fish The meals should be taken.regu-larly and the luncheon and dinner should be approximately equal.

Concomitant cardio-vascular lesions should receive appropriate treatment.

Toward the close, such cases usually require confinement to the house or bed, the diet must be much simplified, tending toward that advised for acute nephritis, meats must usually then be almost entirely eliminated and the tendency to anaemia may be met by the use of iron, which is also indicated in inorganic form or as a vegetable acid salt, for its supposititious astringent action on the kidneys.

Chronic Parenchymatous Nephritis cannot be separated from the interstitial form with any certainty, as regards the dietetic causes nor is any given case of chronic nephritis purely of either type. Genuinely chronic cases of nephritis, that is to say those which do not exist as a protraction of an acute parenchymatous case and which last for years, are mainly of the interstitial type.

Cases, in which the parenchymatous element is important, usually tend either toward dropsy or toward uraemia, the distinction sometimes being surprisingly clear cut. In these cases, there are also usually more complications due to the heart and to gastric function, which embarrass the dietetician, than in more strictly interstitial cases.

In dropsy, the water and salt should be restricted, but excessive thirst and concentration of urine should be avoided.

The appearance of uraemic symptoms usually requires the temporary suspension of feeding and the use of hot physiologic salt solution by bowel. When it becomes necessary to nourish or when the uraemic manifestations are slight, it is best to use an exclusive milk or milk-cereal diet, returning to a fuller diet, as for interstitial nephritis, when the symptoms abate.

Predigestion and the use of small, rather frequent meals, is often required in this type of cases, on account of the cardiac condition and the reaction upon the digestive function.

Amyloid Disease, if recognized, requires the diet appropriate to the. underlying tuberculosis, syphilis or septic state, modified in each instance, according to the functional capacity of the kidney.