ESSAY-REVIEWS 273 



In these writings lie the first ideas, the germs and the 

 principles of most of the discoveries of our age, so that Bacon 

 may justly be considered as the father of modern science and as 

 the begetter of experimental science. Some of his ideas bore 

 very practical fruit in the time near to him : for instance, 

 Columbus says, in a letter to Ferdinand and Isabella, that 

 among the things which determined him to start on his great 

 voyage was that portion of the Opus Majus which was incor- 

 porated without acknowledgment by Petrus Alliacus in his 

 Imago Mundi, in which Bacon asserts the possibility of going 

 westward from Spain to India. Humboldt says that this had 

 more to do with the discovery of America than the advice and 

 teaching of the astronomer Toscanelli. Bacon first divined, 

 what to us is now only a commonplace, the rigorous necessity of 

 controlling by positive experiment the affirmations of speculation 

 and of reasoning. He did not wish to clip the wings of the 

 human spirit to the space of a laboratory or of a dissecting-room, 

 but he urged that inquiry should begin with the simplest objects 

 of science and should extend gradually to the more complex, 

 every observation being controlled by experiment. In chemistry 

 his views rested on the work of the Arabian pioneers, Geber and 

 Avicenna, and he did not, perhaps, do more actual work than 

 Albertus Magnus ; but he saw what the possibilities of chemistry 

 were to a much greater degree than any of his contemporaries. 

 He knew and judged the superstition of his time, but he kept 

 himself above it by his knowledge and judgment. Goethe says 

 that " the writings of Luther contain much more superstition 

 than those of Roger Bacon." But he, to whom so much of the 

 magic of nature had unfolded itself, knew T that many natural 

 phenomena (especially optical) could be made to appear to the 

 ignorant as supernatural. He knew, too, that minute quantities 

 of certain substances can destroy the red colour of copper, or the 

 yellow colour of gold, and also the extraordinary effect of a 

 small quantity of mercury on tin, or of lead on gold, so that it is 

 not to be wondered at that he was looked upon as a magician or 

 necromancer. These examples of natural magic are wonderful 

 even to-day. His idea of the Aristotelian elements is character- 

 istic; he imagines that each of the elements is convertible into 

 the nature of another element ; he says further, " barley is a 

 horse by possibility, that is occult nature, and wheat is a possible 

 man, and man is possible wheat." His idea is that all things 



