When we reflect that the object of digestion is to furnish materials for the growth of the body, and to supply the waste which the system is constantly undergoing, it must appear self-evident, that, if the digestive powers be impaired by disease, by improper quantity or quality of food, or by any other cause, the result must necessarily be the formation of an imperfect chyle, and consequently of imperfect blood. The elements of the blood are derived from the chyle, and if _it_ be vitiated, the blood also must suffer; if the blood be impoverished, so must necessarily be all the organs which it supplies; and if the body be thus debilitated, can any wonder be felt that it should no longer be able to resist the action of offending causes which full health alone can withstand? No matter whether the imperfect chyle springs from deficiency or excess, from too weak or too strong food, from constitutional debility or the inroad of disease,--imperfect nutrition is its invariable consequence, and that cannot happen without exposing the system to morbid influences in a greater or less degree, according to the nature of the constitution and other concomitant circumstances. Wisely, therefore, does Dr Clark recommend early and earnest attention to a proper dietetic regimen, and insist that “the food of the child be regulated chiefly by the state of the digestive organs. In proportion to the delicacy of the child, the diet will in general require to be mild; when he thrives upon milk, farinaceous food, and light broths, no stronger or more substantial food need be used during the first two years of life: when he looks healthy and grows, and his bowels are regular (for this is one of the surest indications that the food is suited to the digestive organs), we have the best proofs that the diet agrees with him. When, on the other hand, the child appears heated or flushed towards evening, when he drinks greedily and more than is usual in children of the same age, and when his bowels do not act regularly, we may be assured that there is something wrong in the regimen employed.