42 



SCIENCE 



I'M. B. Voi;. L. No. 1280 



cumstances wliicli surround the first visit. He 

 was continually employed throughout life in 

 typical German propaganda, and was ac- 

 customed to political deceit. In 1669, under 

 the guise of a Catholic Polish nobleman, he 

 wrote a tract which undertook to mathemat- 

 ically demonstrate to his supposed country- 

 men, the Poles, that it was for the best inter- 

 ests of Poland to elect the German candidate 

 for their throne. The political mission which 

 brought him to Paris in 1672 was to secure 

 Prance as an ally of Germany in a proposed 

 war of conquest against the Turk, the bait to 

 France being the jwssession of Egypt, " one of 

 the best situated lands in the world." This 

 project was finally laughed from the court of 

 Louis XIV. 



While in Paris, Leibniz corresponded with 

 Oldenberg and Collins. The former was Sec- 

 retary of the Eoyal Society of England, and 

 had in charge all papers and manuscripts of 

 the society. He was for many years a German 

 agent in London whose services as secretary 

 were given without pay. Confined in the 

 Tower as a spy in 1669, the Eoyal Society ad- 

 journed its meetings until his release.^ 



Collins was the closest friend of Newton, 

 and spent his entire time in obtaining the 

 latest mathematical information and in corre- 

 sponding with mathematicians about it. 

 These two men, Oldenberg and Collins, always 

 appear as instruments of Leibniz in his deal- 

 ings with London affairs and with Newton, 

 but all communications seem to have passed 

 through Oldenberg's hands. 



After 1669, when Collins obtained the com- 

 pendium of fluxions above mentioned, there 

 was much correspondence about fluxions be- 

 tween Newton, Collins and other mathemati- 

 cians, and on December 19, 1672, Newton 

 sent a letter to Collins which was designed 

 to explain fluxions to any intelligent person, 

 with one illustrative example, which Collins 

 immediately began to communicate to all of 

 his correspondents. 



Leibniz was in London, January 11, 1673. 

 and remained mitil March following. Appli- 



2 See Weld, ' ' History of the Koyal Society, ' ' 

 Vol. 1, pp. 201, 259. 



cation for membership in the Royal Society 

 had preceded him, and he attended all of its 

 meetings, read mathematical papers before it, 

 and made claim to a differential method for 

 series as his own invention, which Pell identi- 

 fied as the method of Mouton, a Frenchman, 

 very much to Leibniz's discomfort. He had 

 discussions with Oldenberg and Collins re- 

 garding series, and we must remember that 

 the latter possessed, in Newton's compendium 

 on fluxions, the latest and most remarkable 

 series of the time. That Leibniz had free 

 access to the manuscripts in the hands of 

 these men, and read them, would appear from 

 his notes of this visit, discovered in 1890, in 

 the royal library at Hanover. These show 

 extracts from Newton's " Optics," and from 

 other authors, and a remarkable absence of 

 notes on mathematics, his chief subject of 

 interest at the time. 



Returning to Paris in March, Leibniz placed 

 himself under the guidance of Huygens in 

 higher mathematics, and began the develop- 

 ment of his calculus. It was well in hand by 

 December, 1675, and the question arose, how 

 to deal with Newton. The plan adopted was 

 to have Newton informed that Leibniz had 

 heard that he had a method for series, tangents 

 and the like, and requested information about 

 it, as he had one of his own. It required the 

 united persuasions of Oldenberg and Collins, 

 and an appeal that it was for the honor of 

 England, to overcome N«wton's objections and 

 bring about the first letter of June 13, 1676, 

 already mentioned. The ostensible purpose of 

 the correspondence is to learn Newton's 

 method, yet he held Newton's compendium of 

 it in his possession for a week, the following 

 September, and since its pages were opened 

 freely to him at that time, it is constructive 

 proof that they were as freely open to him 

 for the two months in 1673 that he was in 

 London. 



The sudden death of Oldenberg in 1677 pre- 

 vented an answer to the letter of " noble frank- 

 ness." but when the " Principia " was pub- 

 lished in 1687, Newton inserted a scholium 

 containing the statement that a letter from 

 Leibniz had shown that that distinguished 



