454 THE POPULAR SCIENCE MONTHLY 



other words, he was anticipating not vaguely, but very clearly and defi- 

 nitely, the conservation of energy. His teaching with regard to the 

 composition of matter was very like that now held by physicists. He 

 declared that matter was composed of two principles, prime matter and 

 form. By forma he meant the dynamic element in matter, while by 

 materia prima he meant the underlying substratum of material, the 

 same in every substance, but differentiated by the dynamics of matter. 



It used to be the custom to make fun of these medieval scientists 

 for believing in the transmutation of metals. It may be said that all 

 three of these greatest teachers did not hold the doctrine of the trans- 

 mutation of metals in the exaggerated way in which it appealed to 

 many of their contemporaries. The theory of matter and form, how- 

 ever, gave a philosophical basis for the idea that one kind of matter 

 might be changed into another. We no longer think that notion ab- 

 surd. Sir "William Eamsay has actually succeeded in changing one 

 element into another and radium and helium are seen changing into 

 each other, until now we are quite ready to think of transmutation 

 placidly. The Philosopher's Stone used to seem a great absurdity 

 until our recent experience with radium, which is to some extent at 

 least the philosopher's stone, since it brings about the change of certain 

 supposed elements into others. A distinguished American chemist said 

 not long ago that he would like to extract all the silver from a large 

 body of lead ore in which it occurs so commonly, and then come back 

 after twenty years and look for further traces of silver, for he felt sure 

 that they would be found and that lead ore is probably always pro- 

 ducing silver in small quantities and copper ore is producing gold. 



Most people will be inclined to ask where the fruits of this under- 

 graduate teaching of science are to be found. They are inclined to pre- 

 sume that science was a closed book to the men and women of that time. 

 It is not hard, however, to point the effect of the scientific training in 

 the writings of the times. Dante is a typical university man of the 

 period. He was at several Italian universities, was at Paris and per- 

 haps at Oxford. His writings are full of science. Professor Kiihns, 

 of Wesleyan, in his book "The Treatment of Nature in Dante," has 

 pointed out how much Dante knows of science and of nature. Few of 

 the poets not only of his own but of any time have known more. There 

 are only one or two writers of poetry in our time who go with so much 

 confidence to nature and the scientific interpretation of her for figures 

 for their poetry. The astronomy, the botany, the zoology of Albertus 

 Magnus and Thomas Aquinas, Dante knew very well and used confi- 

 dently for figurative purposes. Any one who is inclined to think 

 nature study a new idea in the world forgets, or has never known, his 

 Dante. The birds and the bees, the flowers, the leaves, the varied 

 aspects of clouds and sea, the phenomena of phosphorescence, the inti- 



