his belief, that the contents of the former pass into the latter, to be conveyed back to the heart, and from it to be again diffused over the body. In a word, his system appears to have been nearly, or altogether, the same as that which was afterwards taught by the unfortunate Servetus. It is clear, therefore, that Galen had made a very near approach to the Harveian theory of the circulation; indeed, Harvey himself candidly admits this. It will be perceived, from what we have stated, that the grand point of difference between Galen and Harvey, and that upon which the theory of the latter mainly rests, is the question whether or not at every systole of the left ventricle more blood be thrown out than is expended on exhalation, secretion, and nutrition. Upon this point Galen held the negative, Harvey, as we all know, the affirmative. In proof of the opinions which we have attributed to Galen, we refer the reader to ‘An Natura Sanguinis sit in Arteriis;’ ‘Administ. Anatom.’ (vii, 15); ‘de Usu Partium,’ (vi and vii, 7, 8, 9); ‘de Placitis Hippocr. et Plat.’ (i, 5.) See also Averrhoes (Colliget. ii, 8, ii, 9; Collect. i, 9; in Cant. Avic. i, 1); Avicenna (iii, xi, 1); Actuarius (de Spiritu Animali, i, 6; de Causis Urinarum, ii, 2); Nemesius (de Natura Hominis, 24.) With regard to the passages collected by the ingenious M. Dutens and others, from the works of Hippocrates, Plato, Nemesius, Pollux, and Theodoret, to prove that the ancients were acquainted with the circulation of the blood, as taught by Harvey, we shall only remark, that, after having attentively considered them, we cannot but draw the conclusion, that some of these authors must have had, at least, an obscure idea of this doctrine, although, in general, these passages may be understood to refer merely to the lesser circulation and the movement of the blood from the centre to the extremities, as maintained by Galen. See Dutens (Origine des Découvertes attribuées aux Modernes, p. 157); Drelincurtius (de Lienosis Epimetris); and Littré (Introduction aux Œuvres d’Hippocrate.) The last of these writers, whose minute acquaintance with the earlier works on medicine entitles his opinion to every consideration, after a searching investigation into the state of anatomical knowledge in the days of Hippocrates and his immediate successors, comes to the conclusion, that the germ of the theory of the circulation is, beyond doubt, to be found in the Hippocratic treatises. (T. i, 223.) SECT. LXVII.—DIAGNOSIS OF THE TEMPERAMENTS OF THE LIVER.