He got a list of one hundred and fifty shells of the newer pliocene clay on which Etna rests. Nine-tenths of them he found were of species belonging to the present floor of the Mediterranean Sea, and this, to his delight, confirmed what he wrote, and what has already been alluded to, regarding this deposit on a former occasion. At Bronte, Lyell saw the place where a crowd assembled in 1842, to see the lava flow into a great artificial reservoir of water. The torrent of melted stone came forward with a front of more than thirty feet high, and falling suddenly into the water, produced for a while no effect whatever, as if, as in the white hot metal in Butigny’s experiment, it required to cool down before it could cause explosion. At length it went off suddenly, and everybody but one or two out of fifty or more in number was killed. During the years of his journeys in America and Europe, Lyell had paid special attention to the changes which were occurring on the surface of the earth amongst the rocks and hills, valleys, rivers, and sea-shores. He had dealt with inanimate nature largely. About the year 1859 he began to consider the changes which have occurred in the living things of the past, and to direct his attention to the subject of the antiquity of man and to the possible origin of species. He wrote to a friend in his usual half-jesting manner: “I have been much occupied with another geological subject besides that which your niece, Ellen Twisleton, irreverently calls the proving her to be first cousin to a turnip (a violet she should have said); I mean the antiquity of man as implied by the flint hatchets of Amiens, undoubtedly contemporaneous with the mammoth, and also the human skeletons of certain caves near Liège, which I believe to be of corresponding age. I regard the pyramids as things of yesterday in comparison of those relics.” Lyell struggled long in his mind against the theory of the great age of man on the earth, and converted himself to the belief in it, and in 1861 he wrote, after examining the associated remains of human art and extinct animals, such as the mammoth and hairy rhinoceros in England, that “the late discoveries at Herne Bay and Reculver convince me that man inhabited England when the Thames was a tributary of the Rhine.” He published a work on the antiquity of man, and then began to interest himself about the great age when ice reigned supreme over much of the northern hemisphere. Writing to his nephew he states: “On a hill called Moel Tryfaen (in North Wales), at a height of thirteen hundred feet above the sea, I found twenty species of fossil shells, all of living species, in sand and gravel fifty feet thick. You would have known most of them familiarly.” Some of these shells were of kinds now living close by in the sea, but others of kinds now living within the arctic circle. “The shells show that Snowdon and all the highest hills which are in the neighbourhood of Moel Tryfaen were mere