difficulties are much more formidable. But as regards scientific papers, it appears to me that the only considerable impediment is the financial. When the others are overcome, then, and not till then, we shall be in a favourable position for overcoming this also. The reason why the formation of a classified index to scientific papers is comparatively easy, is that the groundwork has been already provided by the alphabetical index of the Royal Society. We have the titles of all scientific papers from 1800 to 1865 before us, and shall soon have them to 1873. Though it might be interesting, it is not essential to go further back. We have now to consider how best to distribute this alphabetical series into a number of subject-indexes. To take the first step we merely require a little money (the first condition of success in most undertakings), and some leisure on the part of a gentleman competent to distinguish the grand primary divisions of scientific research from each other, and avoid the errors which cataloguers have been known to commit in classing the star-fish with constellations, and confusing Plato the philosopher with Plato a volcano in the moon. I need only say that very many of our body would bring far more than this necessary minimum of scientific knowledge to the task. I may instance Mr. Bailey himself. The money would be required to procure two copies of the alphabetical index (which, however, the Royal Society would very likely present), and to pay an assistant for cutting these two copies up into strips, each strip containing a single entry of a scientific paper, and pasting the same upon cardboard. It would be necessary to have two copies of the alphabetical catalogue, as this is printed on both sides of the paper; and as the name of the writer is not repeated at the head of each of his contributions, and would therefore have to be written on the card, close supervision would be required, or else a very intelligent workman. When this was done, the entire catalogue would exist upon cards, in a movable form instead of an immovable. The work of the arranger or arrangers would now begin. All that he or they would have to do would be to write somewhere upon the card, say in the left hand upper corner, the name of the broad scientific division, such as astronomy, meteorology, geology, to which the printed title pasted upon the card appertained, and to put each into a box appropriated to its special object, preserving the alphabetical order of each division. We should then have the classed index already in the rough, at a very small relative expenditure of time, money, and labour. For the purposes of science, however, a more minute subdivision would be necessary. Here the functions of our Council would come into play, and it would have a great opportunity of demonstrating its usefulness as an organising body by inducing, whether by negotiation with individuals or with scientific