The condition of acidosis or acid intoxication may be considered here, first because it is believed by many to be the result of faulty metabolism associated with the diet, and secondly, because the symptoms are largely concerned with disturbance of the gastro-intestinal tract. Clinically, the form of toxaemia under consideration is recognized from the smell of acetone in the breath, from the presence of acetone in the urine and in the vomit, and in severe cases from the presence of diacetic acid in the urine. The symptoms of poisoning may be mild or severe, and probably many mild attacks are recovered from without the condition being recognized. These milder attacks are frequently put down to "biliousness," or constipation, or acute gastric catarrh. In severe cases the leading symptoms are sudden and uncontrollable vomiting, persisting for some hours or days, and accompanied by constant nausea, retching, and great prostration. One form of acidosis in childhood is of unknown origin, and is variously described as "periodic vomiting," "cyclic vomiting," or "recurrent vomiting." Another occurs after the administration of an anaesthetic. We shall consider only the former condition here.

The subject of the dietetic treatment, preventive and curative, of these attacks of periodic vomiting is a very difficult one, owing to our ignorance of the pathology of the affection. This is shown by the number of different views which have been brought forward. At one time the acids in the system were ascribed to the excessive breaking down and imperfect metabolism of proteins. More recently it has been held that the imperfect oxidation of fat in the system is the cause of acidosis. This faulty metabolism may affect both the fat stored in the tissues and that taken in the food. As the carbo-hydrates contain a large amount of oxygen, they should be useful in acidosis from faulty metabolism of fats. This is what actually happens in the acidosis of diabetes, which can be checked by giving carbo-hydrates. On the other hand, Dr. Eustace Smith believes that many cases of periodic vomiting are due to excess of carbohydrates, and the accompanying intestinal fermentation. Dr. Holt also recommends that, in the intervals between attacks, all sugar and sweets should be excluded from the diet, and that the amount of starchy food should be carefully limited. Thus the condition of acidosis has been ascribed by different writers to (1) an excess of proteins, (2) an excess of carbo-hydrates, and (3) an excess of fats in the diet. The excess, however, is not an absolute one, but only relative to the power of the individual to deal with these substances.

Brackett, Stone, and Low say that the formation of acetone is due to faulty metabolism with the formation of free fatty acids, and is largely dependent on a reduction of the carbohydrates and proteins in the diet, and general subnutrition. It may be the body-fat or the food-fat which is the source of the acetone, but the immediate cause is the disturbance of the metabolism. J. A. Kelly says there is some toxaemia present, but whether it is due to the presence of volatile fatty acids, to the rapid destruction of protein matter, or to the rapid elimination of the alkalies it is impossible to say. Langdon Brown says that in acidosis there is a relative starvation of the tissues, and that, broadly speaking, they are being starved of carbohydrates. As a result of this there is excessive disintegration of the fatty tissues in the body. The further production of these acid bodies should be prevented as far as possible by cutting off fat in the diet, and by adding carbo-hydrates.

From the diversity of the views which have been referred to, it is plain that the time has not yet come for any definite or dogmatic statement as to what the diet ought to be in a case of periodic vomiting. During an acute attack the question of diet hardly arises, because the vomiting is so severe that all appetite is lost, and no food can be retained. At this stage thirst is the chief complaint, and the patient may be given frequent sips of hot or cold water, soda-water, or barley-water. Even plain fluids are usually quickly vomited, but there is a certain relief supplied to the patient. If after twenty-four hours the patient is still unable to retain any food by the mouth, nutrient enemata composed of peptonized milk (1 oz.), glucose (half an ounce of a 10 per cent solution) and brandy (half a drachm) may be given every four hours. As soon as food can be retained in the stomach it seems advisable to avoid all fatty material, and to give only digestible proteins and carbo-hydrates. Plasmon, Allenbury's food, and peptonized milk may be given at first, and later one may go on to oatmeal-gruel or porridge, bread, farinaceous puddings, and sugar. As a matter of clinical experience it may be stated that there is no gradual return of the appetite iD typical cases of periodic vomiting, but the attack ceases suddenly, and the patient after sleeping wakes up ravenous and demands food. Further, whatever food is given will be eaten and retained and digested. It is none the less advisable to maintain the above diet for a few days, and thus aid the elimination of the acids from the system.

After an attack has subsided, and in the intervals between attacks the diet usually recommended is one containing an average amount of proteins and carbo-hydrates, and a small amount of fats. All the foods should be simple and digestible, and should be given in such amount as not to overtax the digestive organs. This line of treatment cannot be said to be very efficacious in curing the affection. The fact that in many cases the attacks are slight and pass off after a few days' low diet, or, if more severe, recur only once in six or twelve months, render any exact conclusions as to the effects of diet very difficult.

The present writer has had the opportunity of watching closely two cases in children aged seven and twelve years. In them the attacks were very severe and very frequent. The patients were both extremely emaciated and extremely neurotic. Various diets were tried, including those of an almost purely protein character, and those of carbo-hydrates only. Again, various articles were omitted from the diet for a time, such as milk, then eggs, then meat, etc. No benefit from these various dietetic changes could be observed. When the patients were put on an ordinary full hospital diet they seemed to do just as well as on a restricted one, and further, they gained some flesh. It was then thought that the latter advantage might be still further increased by the Weir-Mitchell system of overfeeding, massage, rest and isolation. The following was the diet taken during a period of six weeks.

Food In Twenty-Four Hours (Patient 12 Years Old)

5 a.m.....Cocoa and milk, ad lib.; bread and dripping.

7 a.m.....Cream 3 1/2; milk, 3iij; water, 3j.

9 a.m.....Milk, 3v; malt extract 3 1/2; water, 3ij;j; bread and dripping.

11 a.m.....Cream, 3 1/2; milk, 3iij; water, 3j.

1 p.m.....Meat; pudding, with cream, 3j; bread and dripping.

3 p.m.....Milk, 3v; malt extract, 3 1/2; water, 3ij.

5 p.m.....Cocoa and milk; one egg; bread and dripping.

7 p.m.....Cream, 3 1/2; milk, 3iv; water, 3j.

9 p.m.....Raw meat juice, 3j; water, 3j; bread and jam.

1 a.m.....Raw meat juice, 3j; water, 3j.

During this course of treatment the patient increased in weight from 43 1/2 lb. to 56 lb., a gain of 12 1/2 lb. There were no attacks of vomiting, and she looked the picture of health. This was the longest interval she had had of freedom from vomiting attacks for some years. The patient was not cured, for on her return to the home surroundings the vomiting returned, and the wasting again set in rapidly. The above experience in two cases is rather against the view that any special food element (protein, carbo-hydrate, or fat) is the cause of the trouble, and supports the view, held by many, that the affection is really to be classed as a neurosis, comparable to migraine. That metabolism is at fault may be admitted, and more especially the action of the liver, but it would appear, in some cases at least, to be dependent primarily on a disturbance of the central nervous system. One may do harm rather than good by a spare diet, or by a non-nutritive diet, or by any diet based purely on the chemical problems of this affection. If a chronic case fails to improve under a rigid and limited diet, it may be advisable to try the effects of a full diet as outlined above.