Fresh milk is better diluted if for use by invalids. In most febrile diseases thirst is excessive, and if considerable quantities of milk are rapidly swallowed, the hard and massive curd which then forms in the stomach is difficult to digest and may tend to increase or induce vomiting, dyspepsia or diarrhoea.
In the acute fevers of short duration, such as malaria and blackwater fever, where the demand for fluid is greater than the immediate necessity for food, the milk given should be freely diluted with soda-water. Where it is less desirable to supply fluid, and nourishment in a concentrated form is required, dilution with barley-water or rice-water is better. The amount added need not be more than half the amount of milk.
Where fresh milk is not available, tinned milk has to be used. The sweetened milks should be avoided. The best tinned milks are those in which the milk is not reduced to a paste but merely concentrated and is still in fluid form. The tin must be carefully examined to see that there has been no second puncture or bulging. The contents must be odourless. A tin once opened must be used quickly. The highly sweetened milks will keep fairly well, but with the unsweetened, and these only should be used for invalids, immediate consumption is necessary.
In making either rice-water or barley-water it is essential that the rice or barley should be washed with many changes of water until the water comes away quite clear, and then boiling water should be poured on and poured away to complete thoroughly the cleaning of the grains. Finally the barley (4 table-spoonfuls to the quart, or rice 2 tablespoonfuls) should be placed in cold water which is slowly brought to the boil and maintained at that temperature for one hour. Till native servants are well trained, much supervision is required, and the washing of rice before making rice-water is apt to be neglected or imperfectly performed, especially by the Chinese.
Chickens or fowls can always be obtained, and chicken broth is on the whole the form of broth best suited for • invalids. In certain countries custom or religion interdicts the use of several kinds of animal food, but chicken broths can be taken by nearly all natives whatever their religion may be.
At times various meat preparations, Liebig's extract, bovril, etc., have to be used, but they should be relied on as little as possible. They apparently keep well, and but few cases of ptomaine poisoning have been attributed to their use.
The dietary during convalescence is most important. Many relapses in diseases both of the alimentary canal and of other organs are due to dietetic errors. The appetite of patients varies; with some after a single short attack of illness it is voracious, and with natives it often takes the form of an intense craving for a heavy meat meal which, if gratified, will usually prove injurious, and may produce a fatal relapse. Part of this craving is due to a too slow return to a liberal dietary, and particularly to unnecessarily prohibiting solid but easily digestible foods. Fish, eggs, milk puddings, bread and fresh vegetables can be allowed early in convalescence in most febrile diseases. Large meals should not be permitted; frequent small feeds are safer. Some food should be provided for the middle of the night, if desired, as an interval of twelve hours between meals is too long for a convalescent who is inclined to be ravenous. In other cases, although the actual disease is over, there is a disinclination for any food; in such convalescence is much retarded. This disinclination may be the result of some complication which requires treatment. Sometimes, as in malaria, it is due to quinine and the consequent atonic dyspepsia. In other cases it is due to anaemia. Change of air has often a markedly beneficial effect. Drugs given by the mouth should be used as little as possible. Forced feeding or undue pressure are not to be employed. Small but tasty and nutritive meals should be provided, and more should not be given at any one time than the patient can easily digest. Fruits are often readily taken under such conditions, and bananas and various other fruits are actually beneficial. Alcoholic stimulants, except light wines, should be avoided. The fluid from the interior of the cocoanut - cocoanut milk - can be taken when quite fresh, but not when there is acute disease of the alimentary canal. It is contra-indicated also where there is flatulence. It must not be drunk in large quantities.
The dietary in most of the tropical diseases is to be regulated largely by the tastes, inclinations and resources of the patient, and controlled by the exercise of common sense and the application of general principles.
Natives of the poorer classes may be assumed to be underfed, particularly as regards nitrogenous food. In chronic, more or less incurable diseases, such as leprosy, the effects of a liberal dietary including abundant fatty substances are most marked, the general condition improving greatly and the disease for a time appearing to retrogress.
Europeans more often have overfed on a highly nitrogenous diet, combined sometimes with the consumption of alcohol in excess of the physiological standard. In such a light, sufficient, but not excessive diet results in an improvement in the general condition.
It is, as a rule, useless to attempt to feed during an acute febrile condition where there is an actual disinclination for food. During convalescence, restraint is necessary; at the same time the patient must not be starved.