20 SCIENTIFIC CATALOGUE. 



Birks (R. B.) ON MATTER AND ETHER ; or, The Secret 

 Laws of Physical Change. By THOMAS RAWSON BIRKS, M.A., 

 Rector of Kelshall, Herts, formerly Fellow of Trinity College, 

 Cambridge. Crown 8vo. $s. 6</. 



The author believes that the hypothesis of the existence of, besides matter, 

 a luminous ether, of immense elastic force, supplies the tru^e and suf- 

 ficient key to the remaining secrets of inorganic matter, of the phe- 

 nomena of light, electricity, etc. In this treatise the author endea- 

 vours first to form a clear and definite conception with regard to the 

 real nature both of matter and ether, and the laivs of mutual action 

 which must be supposed to exist between them. He then endeavours 

 to trace out the main consequences of the fundamental hypothesis, 

 and their correspondence with the known phenomena of physical 

 change. 



Blanford (W. T.) GEOLOGY AND ZOOLOGY OF 

 ABYSSINIA. By W. T. BLANFORD. Svo. 2U. 



This work contains an account of the Geological and Zoological Obser- 

 vations made by the author in Abyssinia, when accompanying the 

 British Army on its march to Magdala and back in 1868, and 

 during a short journey in Northern Abyssinia, after the departure 

 of the troops. Part I. Personal Narrative; Part II. Geology ; 

 Part III. Zoology. With Coloured Illustrations and Geological 

 Map. "The result of his labours," the Academy says, "is an 

 important contribution to the natural history of the country " 



Cooke (Josiah P., Jun.) FIRST PRINCIPLES OF 



CHEMICAL PHILOSOPHY. By JOSIAH P. COOKE, Jun., 

 Ervine Professor of Chemistry and Mineralogy in Harvard College. 

 Crown Svo. 12s. 



The object of the author in this book is to present the philosophy of 

 Chemistry in such a form that it can be made with profit the subject 

 of College recitations, and furnish the teacher with the means of 

 testing the student 's faithfulness and ability. W'i'li this view the 

 subject has been developed in a logical order, and the principles of 

 the science are taught independently of the experimental evidence on 

 which they rest. 



