The foods available are so numerous that we must first of all divide them into classes and consider them in a general way.

These classes have one thing in common, that they contain no uric acid, or very little indeed compared with animal flesh, eggs, or vegetable substances rich in alkaloids, such as pulses, tea, coffee and cocoa, which are, for the reasons given in previous chapters, to be excluded.

The uric acid free foods fall then into the following classes or groups:-

(1) Milk and milk products, as cheese and "protene."

(2) Bread stuffs, cereal foods and glutens.

(3) Nuts and nut foods.

(4) Garden vegetables, as potatoes.

(5) Garden fruits, as apples.

(6) Dried and foreign fruits.

Milk is one of the best of these available foods, because it is easy and quick of digestion, and affords, as we have seen in fig. 2, a supply of albumens and so of force and urea, in a comparatively short space of time.

Many people believe that they cannot take milk, and there are undoubtedly a good many things in ordinary diet with which it does not go very well, as flesh, beer, wine and tobacco; but then the folly is in taking these things at all, not in taking the milk and leaving them out.

Some believe that they cannot digest milk, but this again generally resolves itself into taking it with improper foods, in improper quantities, or at improper times; people who, when they have already swallowed a good and sufficient meal of other things, take down a tumbler or more of milk on top of them, are very likely to have some digestive trouble.

Those who while taking three or four good meals a day, also add a tumbler of milk between times just to keep up their strength, are much more likely to tire out their wretched gastric digestion, and get dyspepsia and debility as a result; but all this cannot be justly charged to the milk, but to the foolish way in which it is taken.

When milk is treated sensibly as a most important food deserves to be, and taken at one or two of the three daily meals, and generally broken up and distributed among the rest of the foods, such as bread, cereals, vegetables and fruits, it is, in the great majority of cases, easily and painlessly digested, and furnishes its proper quantum of albumens, force and urea.

Very much the same applies to cheese, and the bad character it frequently bears is much more often due to the way in which it is taken at the end of a meal already too heavy; or in too large quantity, or insufficiently broken up, rather than to any of its own good or bad qualities.

Cheese contains more albumen than any other of the common foods, and should be taken early in the meal and well distributed through bread stuffs or vegetables; it should be well broken up and masticated, and if hard and the teeth are bad, it should be grated before use.

Those living on a mixed diet rarely require to take more than 2 or 3 ozs. of cheese in a day, that is 1 or 1 1/2 ozs. at two meals, and I have never met any one who could not take this quantity easily and digest it well, when going the right way to work.

Protene is a patent substance prepared from milk by Protene, Limited, 36, Welbeck Street, W., and 141, Kegent Street, W. It is said to be almost pure albumen, and my experiments seem to confirm this statement.

It is specially useful in conditions where the fat or sugar of milk is not required, and I shall have to mention it again in relation to diet for special conditions; but otherwise its digestion and use is much the same as that of cheese (see previous remarks, p. 16), and it may be considered as containing about 2.6 times as much albumen as its own weight of cheese.

It can be obtained in the form of a powder which can be mixed with various other foods, to increase, if necessary, their albumen values; it is also manufactured into bread, gingerbread, and biscuits, which are convenient and palatable.

Plasmon is a very similar substance to Protene, over which it has one advantage that its solutions have but little flavour and can therefore be flavoured to suit any taste. I thus often make use of Plasmon in solution when I wish to replace milk, and Protene Biscuits when I wish to replace cheese, or these substances can be added to make up the quantities of milk and cheese when these are disliked or not well taken; but good milk and cheese are in my opinion always superior to any substitutes, and it is only when fat or sugar have to be avoided, or when milk and cheese are disliked, that we need to resort to them.

Plasmon is to be obtained from the Plasmon Syndicate, 56, Duke Street, Grosvenor Square, W., and it can also be obtained in the form of biscuits, though these generally contain less albumen than those of Protene.

Bread stuffs and cereal foods are often the most important items in the diet list: containing much 4 less albumen than cheese, they are eaten in much larger quantity, and generally form the backbone of the mixed diets, often contributing one half or more of the day's allowance of albumens.

A larger volume than this would scarcely suffice to enumerate their kinds, qualities and preparations, and I must here content myself with saying that they appear to me, especially in the form of bread or biscuit, to furnish a steady and equable supply of albumens over a number of hours, and thus to increase the powers of endurance of those who make use of them, being in this respect at the opposite pole of nutrition from milk or meat.

They often contain a considerable quantity of acid or acid salts, and thus tend rather to keep up the acidity of the urine, and may in conjunction with other things, as acid fruits, lead to some retention of uric acid, especially if aided by the cold weather of winter; but this can be counteracted, as we shall see later on, by eating some potatoes and clothing warmly.

Biscuit is a form of bread stuff which has some advantages, for being dry it not only contains more nourishment in the same weight, but it may be somewhat better cooked than bread; and being dry is an advantage as regards digestibility, as it enables the digestive juices of the mouth to penetrate it more easily.