| Value per lb. | Carbon. | Nitrogen. | |
| d. | Grains per lb. | Grains per lb. | |
| Sugar | 5 | 2955 | — |
| Cocoa | 4 | 3934 | 140 |
| Oatmeal | 2 | 2831 | 136 |
| Pearl barley | 2 | 2660 | 91 |
| Rice | 2 | 2732 | 68 |
| Flour, seconds | 1½ | 2700 | 116 |
| Bread, bakers’ | 1½ | 1975 | 88 |
| Rye meal | 1¼ | 2693 | 86 |
| Peas, split | 1 | 2698 | 248 |
| Maize meal | 1 | 3016 | 120 |
| Barley meal | 1 | 2563 | 68 |
| Carrots | 1 | 508 | 14 |
| Parsnips | 1 | 554 | 12 |
| Beer and porter | 1 | 274 | 1 |
| Treacle | 1 | 2395 | — |
| Potatoes | ½ | 769 | 22 |
| Turnips | ½ | 263 | 13 |
| Vegetables, green | ½ | 420 | 14 |
Digestibility of Foods.—There cannot be the least doubt that in the matter of digestion no rule holds good for all stomachs alike, and it is absurd to attempt to lay down a hard and fast line. At the same time, some idea of the relative period required to digest various substances may be gained from a study of the published results of experiments, though one very doubtful element is left out of the case altogether, namely, the quality of the cooking, which every one knows influences the digestibility of the food. The most complete list is that by Dr. Beaumont, from observation of the process in the stomach of a wounded soldier.
This may be compared with the following table of precedence in digestibility of some animal foods, on the authority of Chambers:—
| Sweetbread and Lambs’ Trotters. | Roast Veal. |
| Boiled chicken. | Boiled Veal, Rabbit. |
| Venison. | Salmon, Mackerel, Herring, Pilchard, Sprat. |
| Lightly Boiled Eggs, New Toasted Cheese. | Hard-boiled and Fried Eggs. |
| Roast Fowl, Turkey, Partridge, and Pheasant. | Wood Pigeon, Hare. |
| Lamb, Wild Duck. | Tame Pigeon, Tame Duck, Goose. |
| Oysters, Periwinkles. | Fried Fish. |
| Omelette (?), Tripe (?). | Roast and Boiled Pork. |
| Boiled Sole, Haddock, Skate, Trout, Perch. | Heart, Liver, Lights, Milt, and Kidneys of Ox, Swine, and Sheep. |
| Tripe and Chitterlings. | Lobsters, Shrimps, Prawns. |
| Mutton. | Caviare. |
| Roast Beef. | Smoked, Dried, Salt, and Pickled Fish. |
| Boiled Beef. | Crab. |
| Rump Steak. | Ripe Old Cheese. |
The contradictions are sufficiently glaring.
From some recent experiments by Jessen it would seem that raw meat is more digestible than cooked, which is perhaps not astonishing when due allowance is made for the way in which that operation is often performed. Thus the times required for digestion were:
Klenze, experimenting on 18 kinds of cheese, found that cheddar was digested in the shortest time (4 hours), while unripe skim Swiss cheese required 10 hours for solution. There is no difference in the digestibility of all sorts of hard cheese, or all soft cheese, but all fat cheeses are dissolved the most rapidly, because, being open by reason of the fat, they are the more readily attacked by the solvent. There is no connection between the digestibility and the percentage of water present in the cheese, but there is some connection with the percentage of fat and the degree of ripeness.
Animal Foods.—There is surely no need to insist on the value of animal foods. At the same time there can be no doubt of a general tendency among town dwellers to eat too much meat. Twice a day is quite often enough for a meat meal, and then it should not form more than about ⅕ of the whole meal. Fresh fish is an excellent and wholesome substitute for meat, especially in the case of brain workers. Cheese is highly nutritious, but digestible only by those living out of doors; this does not apply, however, to the soft cream-cheeses. Lard, dripping, butter, and even butterine or bosch, have great value as heat-producing foods.