HENRY SOTHEU \\ .\ (0., 140, STRAND, W.C., and 3^, PICCADILLY, W. 37i 

 7256 DESCABTES [Latine CARTESIUS] (Rene du Perron) Discours de la Methode pour bien 

 conduire sa raison, et chercher la verite dans les sciences. Plus la DiOPTRKiUE, les Meteores, 

 et la Geometrie, qui sont des essais de cete Methode, premiere edition ; with vignette on title, 

 and numerous woodcuts and diagrams, 4to. contemporary u'hite vellum (very fine copy) ; very 

 RAKE, £5. \os Leyde, Jan Maire, 1637 



First Edition of this celebrated work, the lirst to make known the autlmi s sv>i.iii of ' philosophy (' cogito, ergo 

 sum '), and excessively bare, especially in such line condition. 



The work moreover first contained his treatises on Optics, Meteors, and Geometry, the last, the most celebrated, con- 

 taining his Inventios of Axalvtkal Geometry. The Optics contain the law of refraction, discovered by W. Snellius, 

 which has mistakenly been attribute<l to Descartes, while the treatise on Meteors contains an explanation of numerous 

 atmospheric phenomena, including the rainbow. 



(EuvRES Philosopiiiques (Discours sur la M6thode; Meditations, avec Objections et 



les nieilleurs Textes, avec Introd. par Jules Simon, fcap. 8vo. (pp. 596}, hf. French morocco neaty 

 4* 1844 



7259 Geometria, cum NoTis Florimondi de Beaune, Opera atque Studio Francisci a 



SCHOOTEN ; nunc demum ab eodeni diligenter recognita, locupletioribus Commentariis instructa, 

 multisque egregiis Accessionibus exornata ; with fine engraved portrait by F. v. Schooten, and 

 numerous diagrams^ 4to. contemporary vellum {slighthf water -stained, but a sound copy) ; rare, 

 £1. Is Amst., L. et D. Elzevir, 1659 



a new translation of the Gcoin>:trie, as originally published in the Discours, and specially valuable for the notes by 

 DK Bkaunk, which rendered the difficult original text easy of comprehension, and wherein the editor first prints out that 

 the properties of a curve can be deduced from those of its tangent (' the inverse method of tangents '). 



' Early in 1058 a similar discovery [on the rectification of algebraic curves], independent of that of N .il, wis made by 

 van Heuraet, and this was published by van Schooten inhis edition of Desmrte.'i's ' Geometria ' in 1659.'— H''. IT. R. Hull. 



7260 Editio Tertia, multis Accessionibus exomata, et plus altera sui parte adaucta ; with 



engraved portrait, and numerous diagrams, 4to, sound copy in old vellum, 12* Qd ibidem, 1683 



' It was Descartes who first recognised the true meaning of the negative roots of equations ; and we owe to him the 

 theorem, which is culled by his name, that an equation may have as many positive roots as there are changes of sign in 

 passing from term to term, and as many negative roots as there are continuations of sign, and not more of either kind. 

 He gave a new and ingenious solution of equations of the fourth degree ; and first introduce*! exponents, and thereby laid 

 the foundation for calculating with powers. He showed moreover how to draw tangents and normals at every point of a 

 geometrical curve . . . and what perhaps is his highest merit, he showed how to express the nature and the properties of 

 every curve, by an equation between two variable co-ordinates; thus, in fact, originating Analytical Geometry, which has 

 led tio the brightest discoveries.' — Prof. Aiulrcw Seth l'rin<ih' I'a.ttison. 



7261 : La Geometrie de Rene Descartes, nouvelle Ed. ; with diagrams, cr. 4^10. sewn, 3* 1836 



In this e<lition the modern notation has been substituted for that of Descartes. 



7262 Principia Philosophise, Ed. IV., recognita et Mendis expurgata : Specimina 



Philosophiae, seu Dissertatio de Methodo etc. ; Dioptrice et Meteora : Passiones Anim.e — 

 3 vols. 4to. in 1, with fine full-length portrait, engraved title, and numerous woodcuts; con- 

 temporary English calf ; with booklabel of Daniel Shotivell, Coll. Eman., 1669, 12* Qd Amst., 1664 



7263 Lditiones Ai-TERAE ; loith numerous woodcuts, 3 vols. sni. 4to. in 1, old calf {cracked, 



title slightly damaged, and some II. ivater-stained) , with bookplate of Mr. Henry Reeve, C.B., Is Qd 



ib., Dan. Elzevir, 1672 



7264 E.EDEM ; with numerous woodcuts, 3 vols. sm. 4to. in I, hf. morocco, ivith auto, of Samuel 



Jebb, M.D. (1694-1772), 7* Qd ib., a.e., 1677 



The Friiuipia are for the most part devoted to physical science, and contain the laws of motion and the author's 

 physical theories of the universe, including his once famous theory of vortices, which was only ousted after a supreme 

 reign of nearly a century by Newton's law of gravitation. 



7265 : FouiLLEE (Alfred) Descartes ; ujith portrait after Frans Hals,ica,p. 8vo. buckram, 2s 1893 



7266 : Mahaffy (John Pentland. D.D.) Descartes, with portrait after F. Hals, 12nio. cl., 2s 



Edin., 1880 



7267 DESCHANEL (Augustin Privat) Elementary Trkatise on Natlkal Philosophy; 

 translated and edited by J. D. Everett, f.r.s., 9tli H<1.. v:ith 3 coloured plates and 783 woodcuts, 

 8vo. (pp. 1156), cl., As 6d (p. \8s) 1886 



7268 Tenth Edition, icith 3 coloured plates and 783 woodcuts, 8vo. (pp. 1 148), cl., bs (p. 18.s') 1888 



7269 Part II : Heat, 16th Ed., ivith 140 woodcuts, 8vo. cl., 2s 6d (p. 4* 6d) 1902, or '4 



7270 Part IV : Sound and Light, icith coloured plate and 219 woodcuts, 8vo. cl., 2s 6rf 



(p. 45 6f/) 1903 



7271 DESMAREST (E.) Trait6 de 1'Analvse Indeterminee du Second Degre a Deux 

 Inconnues, suivi de son Application a la Recherche des liacines Primitives, avec Table de ces 

 Kacines pour tons les Nombres Premiers compris entre 1 et 10,000, 4to. sewn, 9* Qd 1852 



7272 DEUSING (Anton) De Vero Systemate Mundi Dissertatio Mathematica, qua 

 Copernici Systema Mundi reformatur; sublatis interim infinitis pene Orbibus, quibus in 

 Systemate Ptolemaico humanaMens di.strahitur ; with numerous diagrams, sm. 4to. FINE COPY in 

 calf antique, r. e., by Mackenzie, with inscr. * BiBLlOTHEC^ COLBERTlNiE ' on title, and bookplate of 

 Henry B. H.Beaufoy, F.R.S. , £2. 2s Amstelodami, Lud. Elzevir, 1643 



Interesting as suggesting a new solar system. The work was unknown to Brunei, Graesse, and Ebert, and is rare. 



7273 DEWAB (Sir James, f.r.s.) On Alchemy in Relation to Modern Science, with folding 

 table, 8vo. (pp. 28), sewn, 2s Qd [1884] 



7274 DIARIAN REPOSITORY (The), or Mathematical Register; containing a Complete Col- 

 lection of all the Mathematical Questions which have been published in the Ladies Diary, 

 1704-60, with their Solutions, by a Society of Mathematicians, numerous diagrams, 4to. con- 

 temporary calf 125 %d 1774 



