The existence of malaria in the ancient times is proved from the chronicles of contemporaneous writers. It appears, moreover, likely that the disease extends to the infancy of the human race, for it is in our day unquestionable that cultivation-especially cultivation of the ground-and malaria are two factors that flourish counter to each other, inasmuch as where husbandry does not exist, malaria is luxuriant, and where the soil is tilled, malaria diminishes and even disappears.

According to W. Groff, malaria was well known to the ancient Egyptians. The word " Aat," occurring among others in the inscriptions on the temple at Denderah, is said to indicate the annual recurring epidemic.

The history of our knowledge of malaria is divided into three epochs by two principal discoveries: the first, the recognition of the specific action of cinchona bark; the second, the demonstration of the malarial parasites by Laveran.

Previous to the discovery of Peruvian bark and its introduction into therapy, malaria was, with other fevers, thrown into a confused conglomeration. Its separation from this confusion was brought about by the effects of the bark, though it was only in our own century that the classification was made absolute. This classification was the result of clinical observation, and especially the study of pathologic anatomy.

Though we may allow, without further discussion, that the ancients had no very clear ideas as to the differentiation of different fevers, it is not true that such a differentiation was not anticipated and earnestly sought. The writings of Hippocrates and Celsus show that they had pretty correct notions as to whether or not a certain fever would terminate favorably, as to the origin of the fever, and as to the causal connection of the fever with its results.

Hippocrates classifies fevers "without evident pain" (therefore without distinct localization of the symptoms) exactly as we do. He writes: "Omitting those arising with evident pain, there are four types, the names of which are: continued fever, quotidian fever, tertian fever, and quartan fever." That the distribution of fevers over different seasons was remarked by Hippocrates is shown by the following quotations: " Of summer, certain of these (already mentioned), and continued, ardent, and tertian fevers," etc.; further: " Of autumn, most of the summer, quartan, and irregular fevers, enlarged spleen, dropsy," etc.

No one would fail to recognize that his irregular fevers refer to relapsing fevers, his enlarged spleen and dropsy, to malarial cachexia.

That Hippocrates appreciated the causal connection between fever and cachexia is evident from many expressions like the following: "This disease is habitual to them both in summer and in winter, and in addition they are very subject to dropsies of a most fatal character ; and in summer dysenteries, diarrheas, and protracted quartan fevers seize them, and these diseases, when prolonged, dispose such constitutions to dropsies, and thus prove fatal. Or: "Convalescents (therefrom) will pass into quartans, and from quartans into dropsies. "

The favorable influence of humidity on fever is shown by: "But if the winter be dry and northerly, and the spring showery and southerly, the summer will necessarily be of a febrile character."

In relation to marsh land and the dwellers thereon he writes: "As to the inhabitants of Phasis, their country is fenny, warm, humid, and wooded; copious and severe rains occur there at all seasons; and the life of the inhabitants is spent among the fens, for their dwellings are constructed of wood and reeds and are erected amidst the waters. For these reasons the Phasians have shapes different from those of all other men; for they are large in stature and of very gross habit of body, so that not a joint or vein is visible. In color they are sallow, as if affected with jaundice. Of all men, they have the roughest voices, "

Hippocrates attributes the origin of the fever to the drinking of contaminated water: "For water contributes much towards health. Such waters then as are marshy, stagnant, and belong to lakes are necessarily hot in summer, thick, and have a strong smell, since they have no current; those who drink them have large and obstructed spleens. . . " (chap, vii).*

Celsus has left us a finished clinical description of intermittent fever and many of its accompanying symptoms. He differentiates a quotidian fever, composed of quartan attacks, and mentions as an especially pernicious fever the malignant tertian That the Romans were very close to the trail in regard to the etiology of malaria is proved from the writings of Varro, Columella, Palladius, Vitruvius, and Avicenna, who made swamps, the emanations from them, and the minute animals living in them, responsible for the disease. This etiologic idea was lost in the middle ages on account of the influence of Galen's teaching, and Morton, at the end of the seventeenth century, was the first again to pick up the thread.**

Mercatus, the court physician to Philips II and III, gives a description of pernicious cases occurring in connection with intermittent fever, and says that they were associated especially with the tertian type. In general, this author is so deeply involved in the humoral pathologic vagaries that pervaded medicine at his time as to be almost totally unintelligible to us.

The Arab physicians also, as Rhazes, Ebn Sina, were acquainted with intermittent fever.

The second epoch began with the introduction of Peruvian bark -the middle of the seventeenth century. Following its opening, in quick succession, came the memorable treatises of Morton, Torti, and Sydenham. The complete clinical pathology of malaria stands out fully developed in the first two especially.

With cinchona in their hands, Torti and Morton divided the "essential fevers" into two principal groups-namely, those that were curable by it, and those in which it had no effect. On the basis of this differentiation Torti built up a description of malarial diseases that must always remain classic. In a clinical way his work has been surpassed by no subsequent writer, and will very probably never be surpassed. Acuteness of observation, wealth of experience, facility of exposition, are the factors that go to make its prominence.