In all that has gone before, health has been presupposed. The modifications necessitated by sickness are of three kinds: 1. The avoidance of such articles of consumption as would increase the disease under the special circumstances, although ordinarily wholesome; 2. The maintenance of the functions or parts of the frame which remain normal; 3. The administration, for a special curative purpose, of peculiar food which would not be recommended for general use.

In all fevers which are classed together as being apparently due to a poison multiplying itself in the blood, the art of diet consists in giving an almost continuous supply of liquid nutriment, holding very soluble aliments in a dilute form. There is nothing so digestible as water, and we take advantage of this high digestibility to get whatever it can dissolve digested along with it. For the first three or even four days, patients, previously strong, should have only farinaceous food, well boiled and cooled to the temperature of the body. Evidence has been already quoted of the power which oatmeal-gruel possesses of sustaining force under the trying circumstances of excessive toil. Now, fever closely resembles muscular effort in its arrest of the digestive functions, at the same moment that it makes an urgent demand for nutriment. With ultra-Egyptian rigor, while straw is withheld, "the tale of the bricks is doubled," and we know by the quantity of urea and phosphates in the urine, and by the foecal excretion, that the muscles and nerves of the bed-ridden sufferer are melting away as fast as if he were scaling the Alps with nothing to eat. It is quite reasonable to transfer the experiences derived from health to sickness, and to feel satisfied that we are not wasting precious opportunities when we are giving fever-patients such a time-honored diet as oatmeal-gruel, care being taken that it is thoroughly well boiled. After three days, the tissues are beginning to suffer, and it is advisable to add chicken-broth, meat-jelly, and strong soup. Let that be supplied which the emaciation shows to be passing away-nitrogenous tissue.

1 Hippocrates, Aphorism XIII.

The administration of alcohol is to be regulated partly by the temperature and partly by the condition of the nervous system. Usually, if the heat of the blood (as taken at the axilla) is above 103°, and always if it is above 105°, there is a necessity for it. Again, if there is great prostration of strength, or tremor of the hands, or quivering in the voice and respiration, if there is low muttering delirium when the patient is left quiet, it is required.

Green-sickness, or anaemia, is characterized by the rapid disappearance of the red particles which float in the blood. To what a strange extent this goes may be seen by looking at the insides of the lips, which naturally hold such a quantity of the fluid as to be quite scarlet, but which now are pale like those of a corpse. It is calculated that the loss of material in marked cases of green-sickness may amount to three pounds of this important constituent of the blood.1 Yet it is capable of complete renewal by diet. If by dint of remedies, notably iron, the appetite can be so regulated as to enjoy meat in excess of the immediate wants of the body, that meat is converted into haematine, and the healthy hue returns to the cheeks as quickly as it left it. "Wine is useful at meals on account of the stimulus it gives to the appetite; it is injurious between meals by spoiling it.

1 Chambers's " Lectures," chiefly Clinical, lect. 11.

Acute rheumatism and acute gout are best treated on an opposite principle. A nutrient nitrogenous diet, which the patient assimilates only too readily, retards recovery, and will even bring on a relapse during convalescence. If meat in any form, solid or liquid, be eaten, it seems to turn to acid, which is already in excess in the blood. The power of fully converting it into living flesh is wanting; and, until this power is regained, a semi-conversion into an organic acid takes place. The redder and more muscular the meat is, the more it disagrees.

Chronic gout is indubitably due to good cheer indulged in either by the sufferer or his ancestors. When a man, day after day, swallows more nitrogenous food than is wanted for the repair of his tissues, the following results may be expected, with variations dependent upon his original constitution : If the digestive solvents are weak and scanty, the excess passes through the canal in an undigested state, and is partially decomposed there. Thereon ensue all sorts of abdominal derangements, which, however, have the advantage of getting rid of the offending matters. If, on the other hand, the stomach secretes vigorously on being stimulated, then, indeed, the excess is digested and absorbed, and is subject to the future changes consequent on assimilation. An active out-of-door life neutralizes this in some measure by augmenting oxidation; much of the albumen goes to form glycogen, and acts as a fuel for the maintenance of muscular force. The balance is wasted in an unexplained way, and does not necessarily injure a hardy frame. The violent muscular exertion and high training needful for oxidation being inconsistent with the habits of intellectual society, a man in the prime of life who puts too much meat into a good stomach habitually retains in his blood an excess of uric acid, into which the nitrogenous waste converts itself. Uric acid in the blood has been distinctly traced as the essence of gout. Perhaps this imaginary first offender develops the full consequences; and that is the best thing that can happen, inducing greater carefulness in future.

These views can suggest but one line of preventive treatment: The children of gouty families should be brought up to a life of strict abstemiousness and muscular activity. From the earliest years vegetables and " meagre" soups should form a considerable portion of their dietary.