Prognosis is an expression of the probable way in which the disease will terminate in any given case. Of course, the wisest and most experienced physicians can do nothing more than express an opinion respecting the result of the disease, since no one can foresee what accidents or unfortuitous circumstances may appear to prevent the result which might otherwise have been favorable. It is also impossible to tell in any given case how long the vital forces of the patient will hold out, or whether the patient has sufficient vital power to bring him to a successful issue. It is evident, then, that any expression respecting the termination of the case should be made with the greatest caution. It is frequently, possible to guess with great accuracy, and a person of experience may be able to form from the various symptoms present and a consideration of the temperament, age, sex, constitution, and the hereditary tendencies of the patient, and also from his present condition and his condition at the beginning of the disease, a very correct estimate of the probabilities in the case. A knowledge of certain symptoms, which observation has shown to be, very frequently, if not always, characteristic of cases which will terminate fatally, is of great service as an aid to a correct prognosis. The following may be mentioned as among the most unfavorable symptoms: Dropsy occurring in connection with some organic disease, as of the kidneys or heart; great emaciation coming on gradually, and steadily progressing in the latter stages of chronic disease; patches occurring on the mouth or in the fauces during the advanced stages of chronic disease; disposition to slide down in bed; delirium in which, al though at home, the patient expresses himself as desirous to go home; persistent drawing of the arm toward the body when an attempt is made to feel the pulse; difficulty in protruding the tongue, or loss of power to do so, together with great trembling when it is protruded; very great difficulty in breathing; obstinate hiccough; what is known as the "Hippocratic countenance," by which is meant the peculiar appearance of the face observed in the last agonies of death,-pinched nostrils, sunken eyes, hollow cheeks, and general aspect of suffering.