positive; but if the practitioner has experience, and if he has the opportunity to make his examinations at suitable times and in a case untreated by quinine, they, too, are conclusive, more especially if supplemented by a differential count of the leucocytes.
The quinine test is generally conclusive in intermittents and in the various larval forms of malaria, but the more severe types of remittents are often singularly resistant to the drug. Moreover, time may not be available in which to test such cases with quinine. They may be cases of a threatening nature in which a speedy diagnosis is of the first importance. In such cases the microscope is the only available trustworthy diagnostic agent.
Periodicity in diagnosis.—— Periodicity at times is a trustworthy enough clinical test for malarial disease. Tertian and quartan periodicity occur only in malarial disease; when either is thoroughly established, its presence is almost conclusive as to the case being malarial. It is otherwise as regards the significance of quotidian periodicity. Quotidian periodicity we find in greater or less degree in nearly all fevers, particularly in fevers associated with suppuration. In hectic conditions quite unconnected with malaria one often sees a quotidian afternoon rigor, followed by hot, dry skin, and a temperature rising even to 103° or 104° F., the febrile movement concluding with a profuse diaphoresis and complete morning apyrexia. Such cases are apt to be misdiagnosed and treated as malarial.
Periodicity of fever in liver abscess; diagnosis from malaria.—— Particularly is this the case in suppuration connected with the liver a condition peculiarly liable to occur in tropical practice. Simulation of malarial fever by hepatic abscess is very common; it is a pitfall into which the inexperienced tropical practitioner often tumbles. In consequence, we find that, at one time or another, most liver abscess cases are drenched with quinine, on the supposition that the associated fever is malarial. There are several points, even apart from an exam-
