October 23, 1903.] 



SCIENCE. 



515 



leaning tower of Pisa that the spell of the 

 Stagirite was broken. Experimental sci- 

 ence now came to the fore, and it was 

 seen that even Aristotelian logic must 

 verify its premises. The authority of evi- 

 dence began to replace the authority of the 

 schools. 



Early in the seventeenth century the 

 atomic philosophy of Epicurus was revived 

 by Gassendi, who was soon followed by 

 Boyle, by Newton and by many others. 

 One other important step was taken also. 

 Boyle, in his 'Sceptical Chyniist,' gave the 

 first scientific definition of element, a con- 

 ception which was more fully developed by 

 Lavoisier later, but which received its com- 

 plete modern form only after Davy had 

 decomposed the alkalies and shown the true 

 nature of chlorine. Without this prelimin- 

 ary work of Boyle and Lavoisier, Dalton's 

 theory would hardly have been possible. 

 An elementary atom can be given no real 

 definition unless we have some notion of 

 an element to begin with. But the strong- 

 est impulse came from Newton, who ac- 

 cepted atomism in clear and unmistakable 

 terms. Coming before Newton, Descartes 

 had rejected the atomic hypothesis, holding 

 that there could be no vacuum in the uni- 

 verse, and making matter essentially syn- 

 onymous with extension. True, Descartes, 

 in his famous theory of vortices, imagined 

 whirling particles of various degrees of 

 fineness; but they were not atoms as 

 atoms and molecules are now conceived. 

 It may be dangerous to pick out landmarks 

 in history and to assert that such and such 

 a movement began at such and such a time. 

 Nevertheless, we may fairly say that the 

 turning point in physical philosophy was 

 Newton "s discovery of gravitation, for that 

 indicated mass as the fundamental prop- 

 erty of matter. For any given portion of 

 matter which we can segregate and identify, 

 extension is variable and mass is constant ; 



when that conclusion was established, the 

 dominance of atomism became inevitable. 

 Boyle, Newton and Lavoisier were legiti- 

 mate precursors of Dalton, but whether 

 Boscovieh should be so considered is more 

 than doubtful. His points of force were too 

 abstract a conception to admit of direct 

 application in the solution of real prob- 

 lems. Dalton certainly owed nothing to 

 Boscovieh, and would just as surely have 

 developed his theory had the brilliant Dal- 

 matian never written a line. 



To Boyle and Newton the atomic hypoth- 

 esis was a question of natural philosophy 

 alone: for, in their day, chemistry, as a 

 quantitative science, had hardly begun to 

 exist. Attempts were soon made, however, 

 to give it chemical application, and the 

 first of these which I have been able to find 

 was due to Emanuel Swedenborg. This 

 philosopher, whose reputation as a man of 

 science has been overshadowed by his fame 

 as a seer and theologian, published in 1721 

 a pamphlet upon chemistry, which is now 

 more easily accessible in an English trans- 

 lation of relatively recent date.* It con- 

 sists of chapters from a larger unpub- 

 lished work, and really amounts to nothing 

 more than a sort of atomic geometry. 

 From geometric groupings of small, con- 

 crete atoms, the properties of different sub- 

 stances are deduced, but in a way which is 

 more curious than instructive. Between 

 the theory and the facts there is no ob- 

 vious relation. The book was absolutely 

 without influence upon chemical thought 

 or discovery, and^ therefore, it has escaped 

 general notice. It is the prototype of a 

 class of speculative treatises, considerable 

 in number, some of them recent, and all 

 of them futile. They represent efforts 

 which were premature, and for which the 

 "Some specimens of a work on the Principles 

 of Chemistry with other treatises.' London, 

 1847. Originally published at Amsterdam, in 

 Latin. 



