Celsus was another distinguished practitioner of the methodic sect, who brought, or greatly contributed to bring, physicians back to the patient study and observation recommended by Hippocrates. He seems to have been a cotemporary of Cassius; and his language alone would place him in the Augustan age. Some late critics have reduced him to that of Trajan. Pliny, however, who dedicates his work to Vespasian Titus, in his sixth consulship, A. U. 830, quotes passages of Celsus, which we still find in his writings; but Trajan only began to reign twenty years afterwards. Pliny-also observes, that Julius Graecinus, respecting vineyards, transcribed the directions of Celsus; but J. Graecinus was murdered by Caligula, according to Tacitus,

6 E 2 and Caligula was himself killed in A. U. 783. Celsus tells us that Themison, in advanced life, had deviated from the precepts of Asclepiades, and Pliny, that Themison was the pupil of Asclepiades, who lived in the time of Pompey. Celsus, indeed, speaks of Themison as still alive, and consequently he must have himself flourished in the latter years of Augustus. Celsus is said to have been a Roman, or perhaps a Veronese; but though he speaks occasionally of his own observations, he was not a regular medical practitioner. Pliny never mentions him in this light; and, when he enumerates the physicians of Rome, the name of Celsus is not included.

Celsus in his medical works has chiefly followed Hippocrates, particularly in his Histories of Diseases and Prognostics, except in relation to critical days; but he is not, as has been supposed, the servile commentator of the Coan sage; for he quotes numerous authors of a later era, and seems to have given a brief abstract of the best systems, in a connected view, though evidently of the methodic sect, and the echo of Themison in what relates to the cure of fevers. He is, indeed, rather an epi-tomeof his predecessor's maxims,than himself an object of historical research; and we shall leave him with remarking, that those who wish to study the opinions and practice of the ancient physicians will find both elegantly, as well as correctly, detailed in Celsus.

We should scarcely have mentioned AEmilius Macer, a physician of this era, who is said to have written on plants, on breeding birds, and on theriaca,but to remark that his works are lost, and that the poem on the Virtues of Plants, ascribed to him, is the production of an obscure monk of the middle ages, or, as has been said, of the physician Odo. Of Servilius Democrates we should also have scarcely spoken, since his era is uncertain, and the subject is too uninteresting to induce us to engage in the disquisition, but that the more laboured composition of the Mithridate and Theriaca is professedly taken from his works by Galen. They were detailed in Greek iambics. Of an uncertain age also is Philo, whose name is preserved in the Philonium, a preparation described, according to Galen, in elegiac verses. In this prescription the corrector of opium is the euphorbium, as in the theriaca it is the squill. He seems to speak of himself as of the family of Asclepiades; but his age, we have said, is doubtful.

Scribonius Largus, of whom we have incidentally spoken, was of an era posterior to that of Celsus, though not so late as has been suspected from his style; a peculiarity satisfactorily explained, by supposing that he wrote in Greek, and that his work was translated by an inferior author. His tract on the composition of medicines contains many choice receipts, collected from different sources, chiefly private collections, and empirical traditions, which are not found to countenance the encomia with which they are introduced. Scribonius highly commends his preceptor, Apuleius Celsus, whose antidote against the hydrophobia he has preserved. Another pharmaceutist of that era was Philenides or Philonides, who wrote, according to Dioscorides, on white hellebore; but the chief author in this department of medicine was Andromachus, perhaps the first who was dignified with the title of archiater, though the honour of priority has been contested in favour of Demo-crates. The title has been equally the subject of controversy, and it has been disputed whether it meant the principal, or the emperor's physician. Galen, indeed, expressly observes, that such were his talents, not only in the medical but in the literary departments, that he was appointed He was the author of the theriaca, still known by his name, whose utility consisted not only in resisting the power of all poisons, but in giving calmness and hilarity, as well as removing the effects of fatigue. In this preparation the troches of vipers were designed to be the alexipharmic, and the opium the cordial, ingredient. This remedy, for more than one thousand five hundred years, enjoyed the highest reputation, and was prepared by kings and noblemen with the most accurate attention. The receipt in Greek verse is preserved by Galen. Andromachus has left no other memorial; but the works of his son are often quoted by Galen, though neglected by later authors, as he is not explicit respecting the preparation of his compositions, or the times of most successfully employing them.

Numerous are the collectors of formulae in this period. Among these are the younger Asclepiades, called, probably for the sake of distinction, charicles, highly commended by Tacitus, and Menecrates, perhaps of an earlier era, who first endeavoured to abolish the medical characters of weights and measures, as liable to be mistaken by transcribers, and to substitute words. The improvement, however desirable, was soon overlooked, and Galen complains that the characters were again employed.

There is much reason to suppose, that, from the time of Celsus, physicians again returned to the more certain road of observation and sound reason; but cither the rage of innovation, or the desire of distinction, excited another sectarist, who, like Asclepiades in a former, and Paracelsus in a later, era, attempted to overturn all that his predecessors had collected. This man was Thessalus Trallianus, who boastingly styled himself, on his tomb, latronice. His father was of the lowest rank, and Thessalus himself without the advantages of education. This is the account, indeed, of Galen, who, on every occasion, eagerly censures him; but we have the evidence of Pliny to convict him of the most disgusting arrogance, and the most consummate ignorance. He gained access to his superiors by flattery, and a subserviency to their pleasures; nor did he profess himself a physician till he had disgraced himself by every species of infamy in their service. His system differed, however, very little from that of Asclepiades and Themison. If, in their opinion, health consisted in the pores being adapted to the fluid, and disease in their being unsuitable, Thessalus thought the same. But in the mode of relief he aimed at changing the state of the solids rather than the fluids. He also was the first who in fever ordered three days abstinence and rest, from which physicians were afterwards called diatritarii. His peculiar pathological opinions introduced a singular language, which has not been properly explained, viz. metasyncrysis and metasyncritical remedies. In the language of the methodic sect, is opposed to the former meaning to mix and unite, the latter to separate.