Hippocrates formed a transition between a period of mythology and that of history. His doctrine was received by contemporaries and by posterity with a veneration akin to worship. No other man ever obtained homage so elevated, constant, and universal. A little later ignorance reigned in the school that he made celebrated. Methods and theories were propagated there under the shadow of his name which he would have disowned. Medical science now changes its habitation as well as its aspect, and from the record of Hippocrates and his work we turn to the fourth period of the Age of Foundation,--namely, the _Anatomic_, which extends from the foundation of the Alexandrian library, 320 B.C., up to the death of Galen, about the year A.D. 200. CHAPTER II. _Age of Foundation (continued).--Anatomic Period: Influence of the Alexandrian Library. Herophilus and Erasistratus. Aretæus, f B.C. 170. Celsus, A.D. 1-65 (?). Galen.--Empiricism: Asclepiades B.C. 100 (?).--Methodism: Theinison, B.C. 50 (?).--Eclecticism. Age of Transition, A.D. 201-1400.--Greek Period: Oribasius, 326-403. Ætius, 502-575. Alexander of Tralles, 525-605. Paul us Ægineta, 625-690._ Fourth, or Anatomic,{030} Period.--As already seen, Alexander the Great and his successors collected the intellectual and natural riches of the universe, as they knew them, and placed them at the disposal of studious men to benefit humanity; their complete value has not yet been exhausted, and never can be. This undertaking was carried out under conditions that made it one of extreme difficulty. Manuscripts were then rare and most costly; but few copies of a given work were in existence, often only one, and these were held almost priceless. Under these circumstances the establishment of a public library and of a museum was an act of philanthropy and liberality simply beyond eulogy, and did more to immortalize the founder of the collection than all his victories and other achievements.