I had myself searched very carefully for any documents that might prove the presence even of single Jews in Cornwall, previous to the time when they were banished the realm by Edward I. But my inquiries had not proved more successful than those of my predecessors. Pearce, in his “Laws and Customs of the Stanaries,” published in London, 1725, shares the common belief that the Jews worked in the Cornish mines. “The tinners,” he says (p. ii), “call the antient works by the name of the Working of the Jews, and it is most manifest, that there were Jews inhabiting here until 1291; and this they prove by the names yet enduring, viz. Attall Sarazin, in English, The Jews Feast.” But in spite of his strong belief in the presence of Jews in Cornwall, Pearce adds: “But whether they had liberty to work and search for tin, does not appear, because they had their dwellings chiefly in great Towns and Cities; and being great Usurers, were in that year banished out of England, to the number of 15,060, by the most noble Prince, Edward I.” At last, however, with the kind assistance of Mr. Macray, I discovered a few real Jews in Cornwall in the third year of King John, 1202, namely, one _Simon de Dena_, one _Deudone, the son of Samuel_, and one _Aaron_. Some of their monetary transactions are recorded in the “Rotulus Cancellarii vel Antigraphum Magni Rotuli Pipæ de tertio anno Regni Regis Johannis” (printed under the direction of the Commissioners of the Public Records in 1863, p. 96), and we have here not only their names as evidence of their Jewish origin, but they are actually spoken of as “_prædictus Judens_.” Their transactions, however, are purely financial, and do not lead us to suppose that the Jews, in order to make tin, condescended, in the time of King John or at any other time, to the drudgery of working in tin-mines. _July_, 1867. XV. THE INSULATION OF ST. MICHAEL’S MOUNT.(89) St. Michael’s Mount in Cornwall is so well known to most people, either from sight or from report, that a description of its peculiar features may be deemed almost superfluous; but in order to start fair, I shall quote a short account from the pen of an eminent geologist, Mr. Pengelly, to whom I shall have to refer frequently in the course of this paper.