P E R P E R is afterwards developed into actual intelligence liriKTrjTos the intellectus acquisitus of the Scholastics. The active reason vous TTCH^TIKOS which effects this develop ment is, according to Alexander, no part of the soul, but simply the divine reason acting upon it. The influence of God upon nature is elsewhere reduced by Alexander, as far as possible, to a mechanical process. Aristotle s ethico- mystical conception of God as the ultimate and tran scendent object of desire is set aside ; and the influence of the deity is represented simply as a diffusion of force, first into the heavens and thence downwards, each lower element receiving less according to its greater distance from the source. The commentaries of the Aphrodisian formed the foundation of the Arabian and Scholastic study of Aristotle. Soon after Alexander s death the Peripatetic school was merged, like all others, in the Neoplatonic. Neoplatonists like Porphyry, lamblichus, Themistius, Dexippus, Syrianus, Ammonius, Simplicius, and Philoponus carried on the work of commenting on Aristotle till the final disappearance of Greek philosophy. For the further history of Aristotelian- ism, see ARABIAN PHILOSOPHY and SCHOLASTICISM. The authorities on whom we depend for our knowledge of the Peripatetics are collected and sifted with exhaustive care by Zeller in the relative sections of his Philosophic der Griechcn (ii. 2 and iii. 1). (A. SE.) PERIPATUS. See MYRIAPODA, vol. xvii. p. 116. PERITONITIS, inflammation of the peritoneum or membrane investing the abdominal and pelvic cavities and their contained viscera. It may exist in an acute or a chronic form, and may be either localized in one part or generally diffused. Acute peritonitis may attack persons of both sexes and of any age. It is sometimes brought on, like other inflam mations, by exposure to cold, but it would appear to arise quite as frequently in connexion with some antecedent injury or disease in some of the abdominal organs, or with depraved conditions of the general health. It is an occasional result of hernia and obstructions of the bowels, of wounds penetrating into the abdomen, of the perfora tion of viscera by disease (e.g., in ulcer of the stomach and in typhoid fever), of the bursting of abscesses or cysts into the abdominal cavity, and also of the extension of inflammatory action from some of the abdominal or pelvic organs. Not unfrequently it is at first localized, and then, spreading onwards, becomes general. The changes which take place in the peritoneum are similar to those* undergone by other serous membranes when inflamed, viz., (1) congestion; (2) exudation of lymph in greater or less abundance, at first greyish in colour and soft, thereafter yellow and becoming tough in consistence, causing the folds of intestine to adhere together ; (3) effusion of fluid, either clear, turbid, bloody, or purulent ; (4) absorption more or less complete of the fluid and lymph. Occasionally shreds or bands of unabsorbed lymph remain, constituting a subsequent danger of strangu lation of the bowel. The symptoms usually begin by a rigor, together with vomiting and pain in the abdomen of a peculiarly severe and sickening character, accompanied with extreme tenderness, so that the slightest pressure causes a great aggravation of suffering. The patient lies on the back with the knees drawn up, and it will be noticed that the breathing is rapid and shallow and per formed by movements of the chest only, the abdominal muscles remaining quiescent, unlike what takes place in healthy respiration. The abdomen becomes swollen by flatulent distension of the intestines, which increases the patient s distress. There is usually constipation. The skin is hot, although there may be perspiration ; the pulse is small, hard, and wiry ; the urine is scanty and high- coloured, and passed with pain. The patient s aspect is one of anxiety and suffering. These symptoms may subside in a day or two, but if they do not the case is apt to go on rapidly to a fatal termination. In such an event the pain and tenderness subside, the abdomen becomes more distended, hiccough and vomiting of brown or blood- coloured matter occur, the temperature falls, the face be comes pinched, cold, and clammy, the pulse exceedingly rapid and feeble, and death takes place from collapse, the patient s mental faculties generally remaining clear till the close. When the peritonitis is due to perforation, as may happen in the case of the gastric ulcer, or the ulcers of typhoid fever, the above-mentioned symptoms and the fatal collapse may all take place in from twelve to twenty- four hours. Further, the puerperal form of this disease, which comes on within a day or two after parturition, is always very serious and is often rapidly fatal. The symp toms are similar to those already described, but in addition there are generally superadded those of septicaemia (blood- poisoning). Chronic peritonitis occurs in two forms (1) as a result of the acute attack ; (2) as a tubercular disease. In the former case, the acute symptoms having subsided, abdominal pain to some extent continues, and along with this there is considerable swelling of the abdomen, corresponding to a thickening of the peritoneum, and it may be also to fluid in the peritoneal cavity. Occasionally a condition of this kind appears to develop slowly without there having been any preceding acute attack. In this form of peritonitis there is considerable constitutional disturbance, together with loss of strength and flesh; nevertheless, although the disease is essentially a chronic one, it is often recovered from. The tubercular form of peritonitis occurs either alone or associated with tuberculous disease of the lungs or other organs. The chief symptoms are abdominal pain and distension, along with disturbance of the functions of the bowels, there being either constipation or diarrhoea, or each alternately. Along with these local manifestations there exist the usual phenomena of tuberculous disease, viz., high fever, with rapid emaciation and loss of strength. Cases of this kind are of grave import, and their tendency is to a fatal termination. In the treatment of acute peritonitis the remedy upon which most reliance is to be placed is opium, which affords relief to the pain, and appears to exercise a certain controlling influence upon the inflammatory process. It requires to be given in considerable quantity, yet with due care, so as to avoid its narcotic action. The old plan of covering the abdomen with leeches is now seldom resorted to ; nevertheless a moderate abstraction of blood by this means in a previously healthy person may contribute to the relief of the pain. Hot fomentations with turpentine or opium applied over the abdomen are of value. The strength must be maintained by milk, soups, and other light forms of nourishment. It is not in general desirable that the bowels should act, and this is one of the benefits obtained by the internal administration of opium. In the simple chronic form the use of iodine externally and of tonics with cod-liver oil internally will be found of service ; while in the tuber cular form remedies are as a rule of little value, but such symptoms as pain, fever, diarrhoea, &c., must be dealt with by palliative measures appropriate to these conditions. PERIZONIUS, JACOB (1651-1715), classical scholar the most distinguished member of a learned Dutch family of that name (Voorbroek in the vernacular), was the eldest son of Anton Perizonius, author of a once well-known treatise, De ratione studii theoloyici, and was born at Dam in Groningen on 26th October 1651. He received his school education at Dam and Deventer, and afterwards studied in the university of Utrecht, where he came under the influence of Graevius and abandoned theology for pure literature. The death of his father and other un toward circumstances involved him in a struggle with various outward difficulties, but the influence of Heinsius and Gra?.vius, who already appreciated him highly, and expected great things from him, ultimately procured for
