In resolving on this undertaking the Council did not propose to task the Society 

 with more than the preparation of a Manuscript Catalogue for use in their own 

 Library ; hut it was hoped that eventually the Catalogue might be printed for 

 general use at the public expense, or by means of funds contributed from other 

 sources, 



The work was accordingly begun without delay, and has been carried on under 

 the superintendence of the Library Committee. Four copies were made of the 

 titles of the Papers to be catalogued ; one set of these has been bound up to 

 form a manuscript " Serial Index," now deposited in the Society's Library, others 

 were reserved to be arranged for printing. 



A large proportion of the Periodical Works containing Titles to be extracted 

 was at hand in the Royal Society's Library, and to these very extensive additions 

 have been made during the progress of the work. Another rich store of materials 

 existed in the Library of the British Museum. Valuable contributions were also 

 supplied by the Libraries of the Chemical, the Entomological, the Geological, the 

 Linnean, the Pharmaceutical, the Royal Geographical, the Royal Medical and 

 Chirurgical, and the Zoological Societies, the London Institution, the Office of 

 Patents, the Royal College of Surgeons, the Royal Institution, the School of Mines, 

 and the University of Cambridge ; and the President and Council gratefully acknow- 

 ledge their obligations to the Governing Bodies and Librarians of these Institutions 

 for the facilities thus afforded. 



With a further view to completeness, printed lists of the Periodical Publications 

 already included were from time to time transmitted to Foreign Academies and 

 Scientific Institutions, with a Circular letter from the Foreign Secretary requesting 

 to be informed of deficiencies which might be supplied by the Libraries of the 

 Institutions addressed. In response to this application a valuable contribution was 

 obtained, through the obliging intervention of W. Ritter von HAEDINGER, of nearly 

 2,000 Titles from the Library of the Imperial and Royal Geological Institute 

 of Vienna, carefully extracted by the Librarian, M. SENONER. Valuable aid was 

 also afforded from Prague through the good offices of Professor John CZERMAK. 



As the preparation of the manuscript approached completion, it became expedient 



