HENRY SOTHERAN & CO., 140, STRAND, W.C., AND 37, PICCADTLLY, W. 329 



6*24 BOYLE (Hon. Robert ; F.R.S. ; founder of the Boyle Lectures] NEW EXPERIMENTS PHYSICO- 

 MECHANICALL, touching the SPRING of the AIR, and its Effects (made, for the most part, in a NEW 

 PNEUMATICAL ENGINE), SECOND EDITION, whereunto is added a DEFENCE of the Author's Expli- 

 cation of the Experiments, against the OBJECTIONS of FRANCISCUS LINUS, and THOMAS HOBBES, 

 with 2 copperplates (one folding), sm. 4to. fine copy in old calf (VERY RARE), 1. 15s 



Oxford, H. Hall, 1662 



Containing the author's invention of an improved air-pump (' machina Boyleana'), 'presenting all the essential qual- 

 ities of the modern machine. By a multitude of experiments performed with it, Boyle vividly illustrated the effects (at 

 that time very imperfectly recognised) of the elasticity, compressibility, and weight of the air; investigated its function 

 in respiration, combustion, and conveyance of sound, and exploded the obscure notion ofafitga vacui.' Agms M. Clerke, 



Tin' u*)ove edition is of special importance, as it first contains what is now known as Boyle's Law. 'The ' Defence against 

 Linus' contained experimental proof of the proportional relation between elasticity and pressure, still known as Boyle's 

 Law. This approximately true principle, although loosely demonstrated, was at once generalised and accepted, and was 

 confirmed by MARIOTTE [under whose name it is generally known on the Continent] in 1676.' Eadem. 



BISHOP SUBNET'S COPY: 



6425 - CONTINUATION of NEW EXPERIMENTS, PHYSICO -MECHANICAL, touching the SPRING and 

 WEIGHT of the AIR, and their Effects. The I. Part, with a short DISCOURSE of the ATMOSPHERES 

 of CONSISTENT BODIES, first edition, with 8 fine plates on copper, sm. 4to. contemporary calf 

 (a sound and large copy) ; RARE, with armorial bookplate of GILBERT BURNET as Bp. of Sarum, 

 1. 5s ib., a. e., 1669 



Specially valuable for giving a description of his air-pump as improved by ROBERT HOOKE, F.R.S., the author's assistant 

 spoken of as the ' second Engine ' in this work. 



6426 - The SCEPTICAL CHYMIST : or CHYMICO-PHYSICAL DOUBTS and PARADOXES, touching the 

 Spagyrist's Principles commonly call'd Hypostatical, as they are wont to be Propos'd and Defended 

 by the Generality of Alchymists, whereunto is pnemis'd Part of another Discourse relating to the 

 same Subject, first edition, sm. 8vo. old sheep (VERY RARE), with bookplate of John Sherwen, 

 M.D., sold J. Cadwellfor J. Croolce, 1661 



One of the most important, as well as by far the rarest, of all the author's writings, especially in the above first edition. 

 It was reprint-d in 1680. The above copy has a duplicate title, reading: 'The Sceptical Chymist: or Chymico-Physical 

 Doubts and Paradoxes, touching the Experiments whereby Vulgar Spagyrists are wont to Endeavour to Evince their Salt, 

 Sulphur, and Mercury, to be the true Principles of Things, Printed for J. Ooifce, 166].' 



'In the 'Sceptical Chymist' he virtually demolished, together with the peripatetic doctrine of four elements, the 

 Spagyristic doctrine of the tria primn, tentatively substituting the principles of a ' mechanical philosophy ', expounded in 

 detail in his ' Origin of Formes and Qual ties ' [q. v. supra].' D. N. I!. 



' In his Sceptical Chymist he criticises the Aristotelia'n and the alchemistic elements, which were still accepted by many 

 of the iatro-ehemical age. He enunciated the axiom that only what can be demonstrated to ba the undecomposable con- 

 stituents of bodies are to be regarded as elements. . . . With a far-seeing glance he looked forward to the discovery of a 

 much greater number of elements than was at that time assumed, at the same time contending that many of the substances 

 then held to be elementary were not really so. ... Boyle was the first to state with perfect clearness that a chemical 

 compound results from the combination of two constituents, and that it possesses properties totally different from those 

 of either its constituents alone, thus enabling him to draw a sharp distinction between mixtures and chemical compounds.' 

 Prof. E. v. Meyer. 



6427 SOME CONSIDERATIONS touching the USEFULNESSE of EXPERIMENTAL NATURALL 



PHILOSOPHY, propos'd in a Familiar Discourse to a Friend, by way of Invitation to the Study of 

 it, 2nd Ed., 4to. original calf, Ws Qd Oxford, H. Hall, 1664 



Containing an interesting preface by ROBERT SHARROCK, Archdn. of Winchester. 



' I scruple not to acknowledge there are things that incline me to suspect, that some in the world . . . may have 

 Arcana, to which most of the Processes I reserve may prove little more than Trifles '.Author's preface. This passage is 

 interesting as first avowing his belief in alchemy. 



6428 TRACTS containing New Experiments, touching the RELATION betwixt FLAME and AIR. 



And about EXPLOSIONS. An HYDROSTATICAL DISCOURSE occasion'd by some Objections of 

 DR. HENRY MORE against some Explications of New Experiments made by the Author, with an 

 Hydrostatical Letter, dilucidating an Experiment about a Way of Weighing Water in Water. 

 New Experiments of the POSITIVE and RELATIVE LEVITY of BODIES under Water, of the Air's 

 Spring on Bodies under Water, and about the Differing Pressure of Heavy Solids and Fluids, 

 first edition, large 12mo. old calf, or, old sheep (RARE), 16* Qd R. Davis, 1672 



Containing the author's important investigations on specific gravity. 



It includes chapters 'Of the Difficulty of producing and preserving Flame without Air', 'Of the Propagation of 

 Actual Flame in Vacuo Boyliano ', ' New Experiments about the Relation betwixt Air and the Flamma Vitalis of Animals ', 

 ' Of the Pressure of the Air's Spring on Bodies under. Water ', etc. etc. 



6429 TRACTS : containing I. SUSPICIONS about some HIDDEN QUALITIES of the AIR ; with 



Appendix touching CELESTIAL MAGNETS, and some other Particulars. If. ANIMADVERSIONS 

 upon MR. HOBBES'S Problemata de Vacuo. III. DISCOURSE of the CAUSE of ATTRACTION by 

 SUCTION, first edition, 12mo. old calf, newly rebacked (RARE), 17s Qd M. Pitt, 1674 



Containing also a chapter on the ' Preservation of Bodies in Vacuo Boyliano '. 



6130 [ ] TRACTS consisting of OBSERVATIONS about the SALTNESS of the SEA : ACCOUNT of the 

 STATICAL HYGROSCOPIC and its Uses ; the FORCE of the AIR'S MOISTURE ; the Natural and 

 Preternatural State of Bodies, and a Sceptical Dialogue about the POSITIVE or PRIVATIVE 

 NATURE of COLD, with some Experiments, by a MEMBER of the ROYAL SOCIETY, first edition, 

 sm. Svo. old sheep, newly rebacked IRARE), 17s Qd E. Flesher, 1674 



6131 [ ] SECOND EDITION, sm. 8vo. original sheep, 129 Qd S. Smith, 1690 



Describing some of the author's most interesting investigations, and exploding the Aristotelian doctrine then held that 

 the saltness of the sea was found only on its surface. He also explains the origin of the salts in the sea, shows how to 

 make sea water drinkable by distillation and free/ing, and ascertains its density. 



6432 BRACKENBURY (Charles Ernest, A.M. r.c.E.) BRITISH PROGRESS in GAS WORKS' PLANT 

 and MACHINERY, with 113 illustrations (including 5 plates), roy. Svo. boards, 3s Qd (p. 6? nett) 1905 



6133 BRADLEY (Thomas) PRACTICAL GEOMETRY, LINEAR PERSPECTIVE, and PROJECTION, 

 including Isometrical Perspective, Projections of the Sphere, and the Projection of Shadows, with 

 Description of the Principal Instruments u?ed, etc., 8 plates and numerous woodcuts, Svo. cl.j 

 3s d ft. D U. K. [1834] 



