Apparently they had not yet learned that these substances possess properties which exert a curative action in certain diseases. On the other hand, he mentions the manner of extracting quicksilver, by chemical means, from cinnabar [red sulphide of mercury], the steps required for preparing acetate of lead, and the proper way of making lime water. The work to which reference has been made above was published by Dioscorides about the year 77 A. D. It is the earliest pharmacological treatise that has come down to our time, and for many succeeding centuries it served as the authoritative guide in all questions relating to drugs. The first printed edition of the Greek original appeared in Venice in 1499, but a still earlier Latin version was issued in 1478. According to Pagel the best edition (in Latin and fully illustrated) is that of Pietro Andrea Mattioli, which was printed in Venice in 1554. Neuburger commends highly the German version by J. Berendes. (Stuttgart, 1902.) Of Caelius Aurelianus we possess no biographical details beyond the facts that he was a native of Sicca in Numidia, Africa, and that he lived toward the end of the fourth or during the first part of the fifth century of the present era. He was the author of several works, all but one of which, however, have been lost. The single treatise which has come down to our time treats of acute and chronic diseases, and is spoken of by Daremberg as being virtually a translation of one of the lost writings of Soranus. This book, says Haeser in his History of Medicine, is the most important source from which our knowledge of Methodism is derived; and Neuburger not only agrees with this statement, but adds that the treatise of Caelius Aurelianus played a most important part, toward the end of the Middle Ages, in the evolution of medicine. Up to the present time no translation of this work into any modern language has been published, but Neuburger furnishes a very full analysis of its important parts. In two places, as appears from this analysis, Caelius Aurelianus mentions--among the signs and symptoms of certain affections of the respiratory apparatus--phenomena which show beyond a doubt that he (or Soranus) was familiar with auscultation of the chest. The words which he uses are these:-- “_Stridor vel sonitus interius resonans aut sibilans in ea parte quae patitur,” and “sibilatus vehemens atque asper in ultimo etiam pectoris resonans stridor._” CHAPTER XV CLAUDIUS GALEN