Professor Karl Pearson, the eminent authority on biometrics, writes to Nature of May 6, inquiring where a number of medical journals, or certain years of such, can be found in England, stating that they have been looked for at the likely places and it is possible that they exist and have not been found. It seems a curious thing that London, with its library of the British Museum and all its other medical and general libraries, should lack copies of such widely quoted periodicals as Lo Spallanzani, the Archiv f. Psychiatrie u. Nervenkrankheiten for the eighties, the International Medical Magazine, etc. There seems also to be no library in London containing a complete set of university dissertations and degree theses. This last probably would be found to be the case also in many, if not all, of our American libraries, though there are opportunities occasionally of acquiring them at comparatively