Health consists in the perfect and harmonious admixture of these various elements; but we must assume, in addition, that the body is free from pain, and that there is no obstacle to the due performance of the functions. From this idea of health we may easily form the con ception of disease. It is that state of body in which the functions are in any way interrupted. It depends upon some disproportion in the constituent elements, or some unnatural condition of the organs. The causes of disease are divided by Galen into occasional and predisposing. The predisposing causes are supposed to depend upon some degene ration of the humours. This degeneration was called by him a putre faction. Thus the quotidian fever is referred to putrefaction of the mucus; tertian, to that of the yellow bile ; and quartan, to that of the black bile—this last humour being slow of motion, and requiring a greater time for the completion of the paroxysm. It was upon this theory of the of the humours that the practice of physicians was founded for centuries after the death of Galen, and their remedies were directed to the expulsion of the supposed offending matter. Inflammation depends, according to Galen, upon the paesa;e of the blood into those parts which in their normal eonditiou do not contain it. If the blood be accompanied by the spirits, the inflam mation is spirituous ; if the blood penetrates alone, it is phlegmenous. Erysipelatous inflammation is caused by the admixture of bile; cedematoua, by that of mucus; aud schirrous, by the addition of black bile. The same divisions of inflammation are still retained by syste matic writers, but we are oontent to abstain from referring them to these assumed causes.
The reputation of was established upon the general reception which his theories met with, and his passion for theorising was so great that he has left us but few good descriptions of disease. In these his principal object seems to have been to display his own talent for prognosis. From a character like this we are not to expect much information in the application of particular remedies, but the general principles which he lays down in respect to indications of treatment are worthy of notice. He directs us to draw our iudicatioua especially from the nature of the disease; but if this be undiscovered, from the influence of the seasons and the state of the atmosphere, from the constitution of the patient, his manner of living, or his strength, and in some few instauces from the accession of tho disease. He is said to have occasionally performed surgical operations, but during his stay in Rome he commonly refused to do so, in compliance with the custom of the Roman physicians.
The unbounded influence which the authority of this great and learned physiciau exercised over the minds of his successors, unques tionably contributed to retard the progress of medicine ; for while physicians were occupied iu the study of his works, and in vain attempts to reconcile the phenomena of nature with the dicta of their master, they had little time aud less inclination to interrogate Nature herself, and pursue the study of medicine in those fields in which alone it can be followed with success.
Galen was a most voluminous writer. Though many of his works are said to have been burnt in his house at Rome, and others in the course of time have been lost, there are still extant 137 treatises and fragments of treatises, of which 82 are considered undoubtedly genuine.
From 30 to 50 treatises are still in manuscript, and 168 are mentioned as the akcertained number of those that are lost. The writings of Galen are valuable, not only for the history of medicine, but the great variety of mheellaneoue matter which they contain.
Numerous editions of his works have been published, and several Latin translation", since the discovery of printing. Five Latin editions of the collected works of Galen acre published before the Greek text : the drat Latin edition is that by Bonardus, Venice, 1490, 2 vols. fol.
Philosophies' was printed by Aldus in 1497, together with some treatises of Aristotle and Theophrastus ; and in 1525 the same printer published the first complete edition of the Greek text at Venice In 8 vole foL, which was edited by And, and Fr. .Asulanum, and was dedicated to Clement VII. The text of this edition was by no means correct, but the itupre-sions on large paper are searee and valuable. An edition was published at Basel, 1562, in 4 vole foL, with prolegomena, by the naturalist Gainer. His treatises, 'De Method° Medendi," De Naturali Facultate," De &albite Tuenda,' were translated by our countryman Linacre; and an edition of his treatise, ' De Sanitate Tuenda; and of some other work., was published by Calus. More recently an edition in Greek and Latin has been pub lished by C. G. Kuhn (20 vols. 8vo, Lipei 1821.33). Most of the writings of Galen exist also In Arabic, and memo in Hebrew translations. The reputation of this great writer was for a long time as unbounded and his authority as absolute among the Arabs as among the physicians of Europe.
(Harvey, Exercit. A notoin. ; Sprengel, History of Medicine; Clark, Report of it ;gismo' Paysiolegy, front tAs Trans. of Brit. Assoc., 1834; Fabriciue, Bib. Crag; Choulant, Handbuch der Bacherkinde fur die Aeitere Medici's.)