theories of sickness, which attribute its cause to spirits, including those of the dead, or to the witchcraft, the mana, of some living human being, or ascribe it to the loss of the soul or some part of the soul. In so far as it is ascribed to demonical possession he distinguishes three phases. In the first all sickness of whatever nature is attributed to possession. The Sakalava of Madagascar, in the first phase, explain by the Tromba, or intrusion of an ancestor into the body of the patient, rheumatism, chronic bronchitis, asthma, blood-spitting, erysipelas, marsh-fever and many other diseases. This possession in the second phase is limited to intellectual disorders and to those manifested by convulsive movements or displaying a lack of internal control; and among these he numbers epilepsy, idiotcy, madness, delirium, and uncontrollable rage. In the third place, while some of these are recognised as of natural origin, patients suffering from deep-seated nervous trouble, generally hysterical, and holding themselves to be possessed, are still so recognized. But the author looks forward to a time when the scientific spirit will have so far triumphed that in no civilized land will any malady be explained by possession. Under the influence of the three theories described the attempt is everywhere made to combat disease by mystical means. Sorcerers and shamans devote themselves to driving out the intrusive spirit, or conquering the malign influence, or finally fetching back the missing soul; and while most of the means they employ are useless, sometimes they fall back on plants and other substances which have a really curative power, sedative or otherwise.
The most valuable part of the work is, however, to be found in his analysis of the means employed in sacerdotal therapeutics. He considers with some care the remedies and processes of the priests of Æsculapius and other sacerdotal physicians of classical and pre-classical antiquity, discusses incubation, autoscopy (in which the patient in a somnambulous condition divines his own disease and prescribes for himself), and heteroscopy (in which he does the like for others). Dismissing these as charlatanism he insists that observation and the accumulation of experiences must have led to the empirical treatment of the
