_Relapsing fever_ generally follows epidemics of typhus fever, and is greatly favoured by starvation. Ophthalmia has been chiefly prevalent in charity schools in which the children are underfed, though its essential cause is contagion.
=Diseases Connected with Over-Feeding.=—A fire may go out for want of fuel, or from becoming choked with ashes; and it is the latter state of things which occurs in =Gout= and allied diseases. Weakness is commonly complained of, but this is due to excess of food embarrassing vital action; and abstinence and exercise are required to restore the balance. Excess of nitrogenous food—especially if combined with the use of sweet, or strong, or very acid wines, and beer—is particularly prone to produce gout. In these cases, animal food should only be taken once a day, and vegetable food should be allowed to preponderate.
=Obesity= is favoured by excess of starchy food and sugar, and by copious drinking of water or other beverages. The plan of curing obesity by restricting oneself almost entirely to meat food is only advisable, however, under certain conditions. =Gall-stones= are favoured by rich foods and excess of sugar; also by alcoholic indulgence. =Dyspepsia= is commonly due to loading the stomach at too frequent intervals; but on the other hand, it not infrequently leads to the taking of insufficient food, because of the discomfort produced. The result of this is that a chronic starvation results, with impaired vital powers. Dyspeptic patients should abstain from pastry and from tea and coffee, except in small quantities. Alcohol in any form, as a rule, does harm. Not uncommonly mastication is imperfectly performed, and a good dentist may cure the indigestion which has resisted all other treatment.
The importance of a duly proportioned and sufficient dietary is shown by its great influence on health and constitution. An ill-proportioned or deficient diet is certain to lead to failure of health. The anatomy of an animal may be modified in the course of generations by altered diet, as well as its character; thus, the alimentary canal of the cat has increased in length to adapt it to its omnivorous habits. In the case of the bee we have a still more remarkable instance. If by any accident the queen bee dies, or is lost, the working bees (which are sexually undeveloped) select two or three eggs, which they hatch in large cells, and then feed the maggot on a stimulating jelly, different from that supplied to the other maggots, thus producing a queen bee.