That the _Natural History_ was well known as a whole at least by the close of the middle ages is shown by the numerous editions, some of them magnificently printed, which were turned off from the Italian presses immediately after the invention of printing. In the Magliabechian Library of Florence alone are editions printed at Venice in 1469 and 1472, at Rome in 1473 and Parma in 1481, again at Venice in 1487, 1491, and 1499, not to mention Italian translations which appeared at Venice in 1476 and 1489.[148] These editions were accompanied by some published criticism of Pliny’s statements, since in 1492 appeared at Ferrara a treatise _On the Errors of Pliny and Others in Medicine_ by Nicholas Leonicenus of Vicenza with a dedication to Politian.[149] But two years later Pliny found a defender in Pandulph Collenucius.[150] But Pliny’s future influence will come out repeatedly in later chapters. We shall now inquire, first, what signs of experimental science he shows, either derived from the past or added by himself. Second, what he defines as magic and what he has to say about it. Third, how much of what he supposes to be natural science must we regard as essentially magic? II. Its Experimental Tendency [Sidenote: Importance of observation and experience.] It is probably only a coincidence that two medieval manuscripts close the _Natural History_ in the midst of the seventy-sixth chapter of the last book with the words, “_Experimenta pluribus modis constant.... Primum pondere._”[151] But although from the very nature of his work Pliny makes extensive use of authorities, he not infrequently manifests a realization, as one dealing with the facts of nature should, of the importance of observation and experience as means of reaching the truth. The claims of many Romans of high rank to have carried their arms as far as Mount Atlas, which Pliny declares has been repeatedly shown by experience to be most fallacious, leads him to the further reflection that nowhere is a lapse of one’s credulity easier than where a dignified author supports a false statement.[152] In other passages he calls experience the best teacher in all things,[153] and contrasts unfavorably garrulity of words and sitting in schools with going to solitudes and seeking herbs at their appropriate seasons. That upon our globe the land is entirely surrounded by water does not require, he says, investigation by arguments, but is now known by experience.[154] And if the salamander really extinguished fire, it would have been tried at Rome long ago.[155] On the other hand, we find some assertions in the _Natural History_ which Pliny might easily have tested himself and found false, such as his statement that an egg-shell cannot be broken by force or any weight unless it is tipped a little to one side.[156] Sometimes he gives his personal experience,[157] but also mentions experience in many other connections. [Sidenote: Use of the word _experimentum_.]