278 TEE POPULAR SCIENCE MONTHLY 



It is true that both questions and answers in this pioneer book of 

 natural science are usually more amusing than instructive to the modern 

 reader, although Adelard in his prologue says that he is sure his treatise 

 will be useful to his hearers, but not that it will prove entertaining 

 (tractatum . . . quern quidem auditoribus suis utilem fore scio, iocun- 

 dum nescio). Asked why men do not have horns, Adelard first objects 

 that the question is trivial; but when the nephew urges the utility of 

 homs as weapons of defense, Adelard replies that man has reason instead 

 of horns, and that, as a social as well as bellicose animal, he requires 

 arms which he can lay aside in time of peace. Asked why the nose is 

 placed above the mouth, he replies that it serves the head while the 

 mouth serves the stomach. Many of his explanations are grounded 

 upon the hypothesis current since the Greek philosopher Empedocles, 

 that all nature is composed of four elements, earth, air, fire and water, 

 and characterized by four qualities, hot, cold, dry and moist. Thus when 

 Adelard is asked why bright students often have poor memories, he 

 answers that a moist brain is conducive to intelligence, and a dry 

 cerebrum to memory. He explains his nephew's weeping for joy to see 

 his uncle safely returned from the Orient by the theory that his exces- 

 sive delight heated his brain and distilled moisture thence. 



But reasoning from a general theory of nature to explain particular 

 phenomena is not Adelard's sole method; he also relies on experience. 

 Nor are all his notions crude and incorrect. While he accepts the long 

 established theory of four elements, he is careful to explain that the 

 earth which we see and call by that name is not the element earth, and 

 that no one has ever touched the element water, or seen the elements fire 

 and air. Every particular object contains all four elements, and in 

 daily life we deal only with compounds. 



Adelard states the eternity of matter as follows: 



And certainly in my judgment nothing in this sensible world ever perishes 

 or is less to-day than when it was created. If a part is dissolved from one 

 union, it does not perish but is joined to some other group. 



When his nephew asks him to explain the working of a magic water 

 jar which they once saw at an enchantress's house, and which had holes 

 in both top and bottom so that the attendant could check the flow of 

 water from the bottom by placing his fingers over the apertures in the 

 top, Adelard accounts for the trick by saying that nature abhors a 

 vacuum. Asked how far a stone would fall, if it were dropped into a 

 hole which extended through the center of the earth, he states that it 

 would fall as far as the center and stop there. 



We have heard Adelard upholding scientific argument and investi- 

 gation against a narrow religious attitude. This position is further 

 illustrated by a contemporary of his, William of Conches in Normandy. 

 William, too, complains that the age is instinctively hostile to new 



