The digestion of animal food, especially meat, is in many cases interfered with by sugars, particularly cane sugar. In this way lactic acid fermentation is induced, and, the proteins being badly digested, it is quite possible for uric acid to be formed in greater proportion by a combination of the lactic acid and the highly soluble urea. People who suffer in this way should take as little carbohydrate as possible at a meat meal, or should consume their carbohydrates at a separate meal. Some support the theory that gout is caused not so much by animal foods as by the maldigestion of fruit and saccharine or carbohydrate foods, the kidneys being unable to excrete the compounds formed, and the tissue spaces being crowded with unmetabolised acid material very liable to precipitate. It is remarkable how quickly a plate of stewed prunes or stewed rhubarb, with a liberal addition of cane sugar, will determine effusion into the joints. If such fruits really aid in alkalinising the blood, it is evident that their alkali does not favour freedom from rheumatic manifestations. It is important to note that uric acid is said to be held in solution in the blood by a chemically pure nuclein acid, viz., thymic or thyminic acid.

The rules for the treatment of gout, as laid down by Minkowski, may thus be summarised: The glandular organs, such as liver, kidney, and sweetbread, all of which contain large quantities of purin bases, must be rigorously excluded from the diet. A moderate amount of meat may be eaten, but wine, and especially beer, with its large content of nuclein in the yeast, should be eschewed. To clear away the purins excreted into the bowel, purgatives should be administered and diuresis should be promoted by copious water-drinking, so that the output of uric acid may be increased. He recommends a diet containing 100 to 120 grams of protein, 80 to 100 grams of fat, and a proportionately small quantity of carbohydrates, viz., 250 to 300 grams, altogether amounting to 2,200 to 2,600 calories. Pastries and rich food should be avoided, as well as medicines directed towards increasing the oxidation of uric acid or increasing its solubility, both of which are impossible.

In Chapter II (Theories Of Metabolism - Continued). we have discussed already the action of enzymes in connection with the metabolism of purins, and emphasised the uncertainty of this factor. Mendel and Mitchell have demonstrated the existence of a uric-acid-splitting enzyme in both the spleen and kidneys of the ox, and show that uric acid is not destroyed by extracts of embryo pig's liver, nor boiled extract of adult pig's liver, but is destroyed by extract of adult pig's liver.

Of more importance, perhaps, in connection with my series of cases, is the fact that while many with powerful digestions and food assimilation can obtain their full allowance of nutriment from a fleshless diet, the average patient in this country cannot, and it is worthy of note that carbohydrate foods induce a greater amount of purin in the faeces than flesh foods, no doubt because they break down a greater number of cells in the intestinal mucous membrane, owing to the difficulty in their digestion and absorption. May not this be one cause of the rheumatism so common in patients on a fleshless and tealess diet? It is certainly worth bearing in mind as a possible explanation of muscular rheumatism in all who are constipated, whether vegetarian or not, for if there be such a thing as auto-intoxication, then the endogenous purins may be absorbed. It may be of interest to note here that Burian suggests the constant production of hypoxanthin in muscle as the source of the endogenous purins, the hypoxanthin being oxidised to uric acid in the muscle.

In any research into the action of purins, the following considerations must always be borne in mind: (1) Personal idiosyncrasy has much to do with the diverse results reported, and in my opinion this is ultimately bound up with the metabolic activity of the cells, and especially the ability of the cells of the mucous membrane to withstand the onslaught of irritants such as purin compounds; (2) small quantities of purin are almost invariably well borne, and only in isolated cases are larger doses not tolerated; (3) the ability to tolerate purins is markedly influenced by disease - for example, neurasthenia, so-called, and kidney ailments where the integrity of the cells of the convoluted tubules is doubtful - yet a man in perfect health with a so-called gouty tendency may tolerate them badly, because they act as irritants to the mucous membrane of the hepatic ducts and produce hepatic insufficiency.

If the observation of Dr. H. C. Ross, that the absorption of xanthin by leucocytes (polymorphonuclear) and lymphocytes (mononuclear) is capable of inducing their division, is verified, an important contribution has been made to the role of uric acid and its allies in causing disease, because this induced cell-reproduction suggests the intense proliferation of tissue associated with cancer.