CHAPTER III. 



HUYGENS. 



28. We have now to speak of a treatise by Hu3^gens entitled 

 Be Ratiociniis in Ludo Alece. This treatise was first printed by 

 Schooten at the end of his work entitled Francisci a Bcliooten 

 Exercitationum Mathematicarum Lihri quinque ; it occupies pages 

 519... 534 of the volume. The date 1658 is assigned to Schooten's 

 work by Montucla, but the only copy which I have seen is dated 

 1657. 



Schooten had been the instructor of Huygens in mathematics ; 

 and the treatise which we have to examine was communicated by 

 Huygens to Schooten w^ritten in their vernacular tongue, and 

 Schooten translated it into Latin. 



It appears from a letter written by Schooten to Wallis, that 

 Wallis had seen and commended Huygens's treatise ; see Wallis's 

 Algebra, 1693, p. 833. 



Leibnitz commends it. Leibnitii Opera Omnia, ed. Dutens, 

 Vol. VI. part 1, p. 318. 



29. In his letter to Schooten which is printed at the beginning 

 of the treatise Huygens refers to his predecessors in these words : 

 Sciendum verb, quod jam pridem inter prsestantissimos totd 

 Gallia Geometras calculus hie agitatus fuerit, ne quis indebitam 

 mihi primse inventionis gloriam hac in re tribuat. Huygens ex- 

 presses a very high opinion of the importance and interest of the 

 subject he was bringing under the notice of mathematicians. 



30. The treatise is reprinted with a commentary in James 

 Bernoulli's Ars Conjectandi, and forms the first of the four parts 



