308 PHILOSOPHICAL TRANSACTIONS. [aNNO I676. 



As to the order which our author has observed in those elements, they are 

 divided into two parts. The first, containing five books, explains and demon- 

 strates both the supputation with numbers, called arithmetic, and that of sym- 

 bols or letters, called algebra. The other, in four books, explains and treats 

 fundamentally of the analytical part, teaching to resolve questions, and to dis- 

 cover the general truths of the mathematics. 



In the last four books he settles first the grounds of analysis. Next, after 

 giving some idea of the method of Diophantus, and of that of Vieta, he is par- 

 ticular in explaining the method of Descartes, which he esteems to be the most 

 general, fertile, and easiest of all. Yet seeing that this famous man has 

 not demonstrated, nor so much as explained, all the principles which he has 

 made use of, our author intimates, that the reader will not find in his writings 

 the same advantages for understanding his analysis, as may be had from these 

 elements. For^ after he has clearly explained and demonstrated all those prin- 

 ciples, he thence deduces in order not only all the discoveries made by Descartes^ 

 but also other new and more useful ones. 



II. De I'Art de Parler; a Paris, 1675, in l2mo. 



To make the reader comprehend the true reasons of the principles of rhetoric, 

 the author begins with explaining how discourse comes to be formed; and 

 there being nothing better than nature herself to teach us the form that our 

 words ought to have for expressing our thoughts and the motions of our will, 

 he represents to himself a troop of men newly born, and that never have spoken 

 before. He considers what these men would do : he shows, that being soon 

 tired with expressing their mind to each other by gestures, they would quickly 

 find the advantage of speaking, and form a language to themselves; he inquires, 

 what form they would give to that language ; and in this inquiry he lays the 

 foundations of all languages, and shows the reason of all the rules prescribed by 

 grammarians, showing that this research is very useful to learn languages with 

 more ease, and to speak them with more exactness. And having made these 

 new men act their part, he declares what has been the true origin of tongues, 

 and that it is not hazard that has made men find out the use of speech; yet 

 showing that speech is subject to men's will, and that custom, or the common 

 consent of men, exercises an absolute power over words; whereupon he gives 

 rules to know which are the laws of custom, and to observe them after he has 

 instructed the reader which are the laws prescribed by reason. 



III. The Manner of Raising, Ordering, and Improving Forest Trees; also 

 how to plant, make, and keep Woods, Walks, Avenues, Lawns, Hedges, &c. 

 with several Figures proper for Avenues and Walks to end in ; and convenient 

 Figures for Lawns ; also Rules and Tables, showing how the ingenious Planter 



