An attractive set of nineteenth-century scientific and mathematical treatises, bound to match.. I) First edition of Avogadro's magnum opus, containing the first announcement of 'Avogadro's Number'. A major treatise containing Avogadro's famous hypothesis that the number of integral molecules in any gas is always the same for equal volumes, or always proportional to the volumes. This was of great importance for nineteenth-century chemistry in effectively distinguishing between atoms and molecules. Avogadro first published this hypothesis in 1811, but it was largely ignored for another half century, partly because it was published first in Italian (when Italy was at the periphery of scientific research) and subsequently only in minor French, German and English scientific journals.

II) First edition of this rare publication, considered an important scientific journal above all for being the means of dissemination of the mathematical theories of A.L. Cauchy in Italy. The second volume contains some of Cauchy's fundamental works translated into Italian, including Sulla meccanica celeste.

III) First publication of Cauchy's equation, which determined the relationship between the wavelength of light and the refractive index of a material the light passes through. Cauchy produced this publication, which consisted of his own papers, in 1835 and 1836. This memoir was issued as eight parts of his periodical Nouveaux Exercices de Mathématiques, and was a successor to his earlier Exercices de Mathématiques, published from 1826 to 1830. A prolific and rigourous mathematician, Cauchy's works covered refraction and polarisation of light, mechanics, elasticity, number theory and complex functions.

IV) The rare first edition of Legendre's great work on the theory of elliptic functions, its application to geometry and mechanics, methods of constructing elliptical tables, Eulerian integrals, etc. This copy is complete with the three supplements published successively in 1828, 1829 and 1832. 'Legendre's research covers all areas of mathematics, including celestial mechanics, but his favourite subjects are elliptic functions and number theory. From 1786, he worked with elliptic integrals. His Exercices de calcul intégral (1811-1816) and the three volumes of his monumental Traité des fonctions elliptiques et des intégrales eulériennes (1825-1828), followed by three supplements in which he expounded the work of Abel and Jacobi, made him the undisputed specialist' (from the French text).

V) Fifth edition of this classic work on geometry. 'Monge should be considered the true creator of descriptive geometry, for it was he who elegantly and methodically converted the group of graphical procedures used by practitioners into a general uniform technique based on simple and rigourous geometric reasoning and methods. Within a few years this new discipline was being taught in French scientific and technical schools and had spread to several other Continental countries' (DSB).

VI) First edition of this apparently unfinished work on analytical mechanics. Statics and dynamics were to have been augmented with hydrostatics and hydrodynamics, and possibly a fifth part giving applications. Scarce - the two parts are not often found bound together.

11 vols in all, comprising: I) Fisica de' Corpi Ponderabili: first edition; 4 vols, thick 8vo; 18 folding plates, scattered light foxing, slight toning to leaves; II) Opuscoli Matematici e Fisici: first edition; 2 vols in one, 4to; 2 folding plates, scattered light foxing; III) Mémoire sur la Dispersion de la Lumière: first edition; 4to; numerous tables to text, many full-page, some browning to leaves; IV) Traité des fonctions elliptiques et des intégrales eulériennes: first edition; 3 vols, 4to; 4 folding plates, lacking portrait of Euler in volume 2, some leaves browned, scattered light foxing; V) Géométrie Descriptive: fifth edition; 4to; 28 folding plates, light dampstaining to prelims, scattered light foxing; VI) Mécanique Analytique: first edition; 4to; 4 folding plates, scattered light foxing, light dampstaining to plates; contemporary half vellum (7 vols) and full vellum (4 vols), bound to match, red and green morocco title labels with gilt lettering, gilt tooling to spines, light wear to extremities, overall an attractive set.

Norman 89; Honeyman 168 (for Avogadro).