Curiosities of Science. 



De Morgan (in Notes and Queries, 2d series, No. 139, p. 169) ques- 

 tions'whether the fruit was an apple, and maintains that the anecdote 

 rests upon very slight authority ; more especially as the idea had for 

 many ye irs been floating before the minds of physical inquirers ; al- 

 though Newton cleared away the confusions and difficulties which pre- 

 vented very able men from proceeding beyond conjecture, and by this 

 means established universal gravitation. 



NEWTON'S " PKINCIPIA." 



" It may be justly said," observes Halley, " that so many 

 and so valuable philosophical truths as are herein discovered 

 and put past dispute were never yet owing to the capacity and 

 industry of any one man." " The importance and generality 

 of the discoveries," says Laplace, "and the immense number 

 of original and profound views, which have been the germ of 

 the most brilliant theories of the philosophers of this (18th) 

 century, and all presented with much elegance, will ensure to 

 the work on the Mathematical Principles of Natural Philosophy 

 a preeminence above all the other productions of human 

 genius." 



DESCAKTES' LABOURS IN PHYSICS. 



The most profound among the many eminent thinkers 

 France has produced, is Rene Descartes, of whom the least 

 that can be said is, that he effected a revolution more decisive 

 than has ever been brought about by any other single mind; 

 that he was the first who successfully applied algebra to geo- 

 metry; that he pointed out the important law of the sines; 

 that in an age in which optical instruments were extremely 

 imperfect, he discovered the changes to which light is sub- 

 jected in the eye by the crystalline lens ; that he directed at- 

 tention to the consequences resulting from the weight of the 

 atmosphere ; and that he moreover detected the causes of the 

 rainbow. At the same time, and as if to combine the most 

 varied forms of excellence, he is not only allowed to be the first 

 geometrician of the age, but by the clearness and admirable 

 precision of his style, he became one of the founders of French 

 prose. And, although he was constantly engaged in those lofty 

 inquiries into the nature of the human mind, which can never 

 be studied without wonder, he combined with them a long 

 course of laborious experiment upon the animal frame, which 

 raised him to the highest rank among the anatomists of his 

 time. The great discovery made by Harvey of the Circulation 

 of the Blood was neglected by most of his contemporaries ; but 

 it was at once recognised by Descartes, who made it the basis 

 of the physiological part of his work on man. He was likewise 

 the discoverer of the lacteals by Aselli, which, like every great 



