accessible to everybody—then we should be in a very different position from that which we occupy at present. I cannot think that so much good work would be allowed to be lost. The catalogue, not being confined to papers in the English language, would be equally useful in every country where science is cultivated, and would find support all over the civilised world. Either from the Government, or from learned societies, or the universities, or the enterprise of publishers, or the interest of individual subscribers, or private munificence, means would, sooner or later, be forthcoming to bring the work out, and thus erect a most substantial monument to the utility of our Association. It would obviously be important to provide that scientific papers should be indexed not only for the past, but for the future. If, as I trust, the Royal Society intends to continue the publication of its alphabetical index from time to time, the compilers of the classified index will continue to enjoy the same facilities as at present. There must be some very effectual machinery at the Society for registering new scientific papers as they are published. What it is we may hope to learn from our colleague, its eminent librarian, who must be the most competent of all authorities on the subject. Mr. Bailey draws attention to several scientific periodicals as useful for bibliographical purposes, and I may mention one which seems to be very complete.[231:1] It is published at Rome. The number for last December, which I have just seen, is so complete that, among a very great number of scientific papers from all quarters, it records those on the telephone and the electric light, in the "Companion to the British Almanac," which, I think, had then been only announced here, not published, omitting the other contributions as non-scientific. It further gives a complete index to the contents of the _Revista Cientifica_, a Barcelona periodical, which had apparently just reached the editor, from its commencement in the preceding April. By this list I learn that the electric pen, the subject of our colleague Mr. Frost's recent paper, had been the theme of a communication to a Barcelona society in May last. It certainly seems as if any library that took this periodical in, and transcribed the entries in its bibliographical section on cards properly classed, would be able to keep up a pretty fair subject-index to scientific papers for the future. I must, in conclusion, say a few words on a subject-index to the transactions of literary societies. The prospect is here much more remote, from the want of the almost indispensable groundwork of a general alphabetical index. We have seen what an infinity of trouble in collecting, in cataloguing, and in transcribing will be saved by the Royal Society's list in the case of scientific papers, and are in a position to appreciate the impediments which must arise from the want of one in this instance.