The Mathematical and other Tracts of the late James M'Cullagh, F.T.C.D. Professor of Natural Philosophy in the University of Dublin. Now first collected, and Edited by the Rev. J.H. JELLETT, B.D. and the Rev. S. HAUGHTON, M.D. Fellows of Trinity College, Dublin, 8vo. 15_s._ Elementary Treatise on the Wave-Theory of Light. By H. LLOYD, D.D. D.C L. &c. late Provost of Trinity College, Dublin. 8vo. price 10_s._ 6_d._ Fragments of Science. By JOHN TYNDALL, F.R.S. Sixth Edition, revised and augmented. 2 vols. crown 8vo. 16_s._ Heat a Mode of Motion. By JOHN TYNDALL, F.R.S. Sixth Edition (Thirteenth Thousand), thoroughly revised and enlarged. Crown 8vo. 12_s._ Sound. By JOHN TYNDALL, F.R.S. Fourth Edition, including Recent Researches. [_In the press._ Essays on the Floating-Matter of the Air in relation to Putrefaction and Infection. By JOHN TYNDALL, F.R.S. With 24 Woodcuts. Crown 8vo. 7_s._ 6_d._ Professor Tyndall's Lectures on Light, delivered in America in 1872 and 1873. With Portrait, Plate & Diagrams. Crown 8vo. 7_s._ 6_d._ Professor Tyndall's Lessons in Electricity at the Royal Institution, 1875-6. With 58 Woodcuts. Crown 8vo. 2_s._ 6_d._ Professor Tyndall's Notes of a Course of Seven Lectures on Electrical Phenomena and Theories, delivered at the Royal Institution. Crown 8vo. 1_s._ sewed, 1_s._ 6_d._ cloth. Professor Tyndall's Notes of a Course of Nine Lectures on Light, delivered at the Royal Institution. Crown 8vo. 1_s._ sewed, 1_s._ 6_d._ cloth. Six Lectures on Physical Geography, delivered in 1876, with some Additions. By the Rev. SAMUEL HAUGHTON, F.R.S. M.D. D.C.L. With 23 Diagrams. 8vo. 15_s._ An Introduction to the Systematic Zoology and Morphology of Vertebrate Animals. By A. MACALISTER, M.D. With 28 Diagrams. 8vo. 10_s._ 6_d._ Text-Books of Science, Mechanical and Physical, adapted for the use of Artisans and of Students in Public and Science Schools. Small 8vo. with Woodcuts, &c. Abney's Photography, 3_s._ 6_d._ Anderson's (Sir John) Strength of Materials, 3_s._ 6_d._ Armstrong's Organic Chemistry, 3_s._ 6_d._ Ball's Elements of Astronomy, 6_s._ Barry's Railway Appliances, 3_s._ 6_d._ Bauerman's Systematic Mineralogy, 6_s._ Bloxam's Metals, 3_s._ 6_d._ Goodeve's Mechanics, 3_s._ 6_d._ Gore's Electro-Metallurgy, 6_s._ Griffin's Algebra & Trigonometry, 3_s._ 6_d._ Jenkin's Electricity & Magnetism, 3_s._ 6_d._ Maxwell's Theory of Heat, 3_s._ 6_d._ Merrifield's Technical Arithmetic, 3_s._ 6_d._ Miller's Inorganic Chemistry, 3_s._ 6_d._ Preece & Sivewright's Telegraphy, 3_s._ 6_d._ Rutley's Study of Rocks, 4_s._ 6_d._ Shelley's Workshop Appliances, 3_s._ 6_d._ Thomé's Structural and Physiological Botany, 6_s._ Thorpe's Quantitative Analysis, 4_s._ 6_d._ Thorpe & Muir's Qualitative Analysis, 3_s._ 6_d._ Tilden's Chemical Philosophy, 3_s._ 6_d._ Unwin's Machine Design, 3_s._ 6_d._ Watson's Plane & Solid Geometry, 3_s._ 6_d._