A HISTORY OF SCIENCE 



A certain manuscript of the great Cornelius Celsus, 

 the De Medicine, which had been lost for many cen- 

 turies, was found in the church of St. Ambrose, at 

 Milan, in 1443, and was at once put into print. The 

 effect of the publication of this book, which had lain in 

 hiding for so many centuries, was a revelation, showing 

 the medical profession how far most of their supposed 

 true copies of Celsus had drifted away from the original. 

 The indisputable authenticity of this manuscript, dis- 

 covered and vouched for by the man who shortly after 

 became Pope Nicholas V., made its publication the 

 more impressive. The output in book form of other 

 authorities followed rapidly, and the manifest discrep- 

 ancies between such teachers as Celsus, Hippocrates, 

 Galen, and Pliny heightened still more the growing 

 spirit of criticism. 



These doubts resulted in great controversies as to 

 the proper treatment of certain diseases, some physi- 

 cians following Hippocrates, others Galen or Celsus, 

 still others the Arabian masters. One of the most 

 bitter of these contests was over the question of " re- 

 vulsion," and "derivation" that is, whether in cases 

 of pleurisy treated by bleeding, the venesection should 

 be made at a point distant from the seat of the disease, 

 as held by the "revisionists," or at a point nearer and 

 on the same side of the body, as practised by the " deri- 

 vationists." That any great point for discussion could 

 be raised in the fifteenth or sixteenth centuries on so 

 simple a matter as it seems to-day shows how neces- 

 sary to the progress of medicine was the discovery of 

 the circulation of the blood made by Harvey two cen- 

 turies later. After Harvey's discovery no such dis- 



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