but I doubt whether it contains much of the tonic quality of Peruvian bark. It is no doubt useful as an antiperiodic, and should be given as in other forms of periodic fever. In most cases, it is probably essential to the cure, but in the later stages it should not be given in large doses. At all times, the dose may be lessened and the tonic effect increased by the addition of arsenic. The carbonate of ammonia, as an excitant, is mostly to be preferred to alcoholic fluids. Effervescing mixtures are grateful and serviceable, and may be given in small quantities very often. Nourishing food is always necessary, but it must be carefully considered that the power of digestion is much enfeebled, and that every particle of food, of whatever kind, which passes through the bowels undigested, increases the already too great irritation. The free use of mucilaginous drinks cannot always be indulged in with safety on this account, and the indiscriminate and unlimited use of even such bland articles of diet must be condemned. The object of food is to nourish and support the body; and that kind is best which is most easily digested, and which supplies the largest amount of nutriment in a given bulk. I am inclined to believe that the best for general use is fresh milk which has been well boiled as soon as taken from the cow. It is more soothing than gum-water, while it affords an ample supply of easily digested nourishment, and is, withal, a good vehicle

for the exhibition of stimulants. It is important, however, that the milk should be boiled, and it is always better to be boiled while fresh, before the lighter particles have time to rise toward the surface. Milk, used in this way, is both nutritious and medicinal in all intestinal irritations; as is also the gluten of flour, entirely divested of the admixture of starch. I commend these two articles of diet, to your constant consideration.

BEFORE dismissing the subject of fever, it is proper that I should say something of that peculiar class called eruptive fevers. The particular forms which will engage our attention are, small-pox, measles, and scarlatina, as proper representatives of the whole class. To these are sometimes added erysipelas, plague, varicella, roseola, dengue, urticaria, and the vaccine disease. Hooping-cough and mumps have also been considered kindred affections, not specially affecting the skin.

The eruptive fevers begin their course with the usual symptoms of fever arising from whatever cause, and in due time they present their characteristic local lesions with wonderful uniformity upon the surface of the body. There are many points of resemblance in the different forms, just as there are, as we have seen, in the various fevers specifically affecting other and internal organs of the body; and we are told that until a recent period the eruptive fevers were considered only as variations of one and the same disease.

The truth is, however, that they are as easily diagnosticated, one from another, as other forms of fever; and even more so, because their characteristic lesions, our principal guide in all fevers, are in these, unlike all others, both visible and tangible. We may conclude, therefore, that they who considered them to be identical, either had not seen the different forms at all, or that they were only very superficial observers in pathology and diagnosis.

These fevers are supposed to be caused by contagion, a mysterious and impalpable influence emanating from the human body while suffering from the disease, and, like the causes of other forms of fever, known only by its effects. All this is, no doubt, true, but it is equally true that eruptive fevers have sometimes appeared, as all must have done originally, without exposure to such contagious emanations. Their spontaneous origin, so called, has not only been proved, but we find the epidemic influence producing them so strong, that their peculiarities are impressed in some degree upon other febrile affections, and even upon healthy subjects who enjoy an exemption from having once had the disease.

As we are not permitted to question the truth of the axiom, like causes produce like effects-in other words, that a particular effect is always due to the operation of the same cause-we must conclude that there are other sources of these causes of contagious

disease than the human body; that whenever these diseases become epidemic, this mysterious essence pervades the atmosphere, and that it exists in varying intensity in different localities, causing more or less of diseased action, such as is peculiar to the prevailing disease, in all subjects who are in a predisposed condition and exposed to the epidemic influence. As to the nature of this cause we know nothing whatever; nor can we have any conception of the differences existing in the various causes of febrile disease, differences which determine the character of the effects produced. As in the case of attraction of gravitation, our knowledge is confined to results.

When any one of these eruptive fevers is prevailing as an epidemic, it is not uncommon to meet with some of its distinctive symptoms, febrile, eruptive, or anginose, without such full development of the disease as will preclude its recurrence at another time, or such as will justify the opinion that the patient, having previously had the disease, has now suffered a second attack. These are effects of epidemic influence, operating upon the system independently of personal contagion, and showing that the morbid effect of a specific cause may be produced in an imperfect degree in subjects who are protected against its entire and legitimate operation. Hence the anomalies observed in this class of fevers. In measles we have the eruption without the catarrhal symptoms,