With all these occupations Sir David found time to invent one of the prettiest of toys, the Kaleidoscope ; to write one of the most charming of popular scientific treatises, the ' Letters on Natural Magic ; ' and to enter into a considerable number of controversies, in which he displayed such a capacity for the outpouring of copious wrath, that his adversaries must have found it difficult to believe that he had anything else to do but to assail them. But this marvellous energy was never directed to geological problems. Sir David was familiar with minerals, but he regarded them with the eye of a student of optics ; and even his discovery of the cavities in crystals and of their contents did not cause him to diverge from his favourite line of study. Once, indeed, he plunged into cosmology ; but ' More Worlds than One ' hardly added to the renown which he had justly obtained as an unwearied observer and accumulator of facts in optics.
Dr. Eugene Francfort, Commendatore of the Order of St, Maurice and St. Lazarus, whose sudden decease took place at Pallanza, on the 22nd September 1868, had for some years directed the application of English capital to the working of numerous mines near the Lago Maggiore and in the Val Anzasca. He had in early life worked at chemistry and geology in the United States, and when established in Italy exhibited such enthusiasm in the pursuit of mineralogy as secured him the friendship of many scientific men of eminence in that country. His liberality, a rare virtue among collectors, will not soon be forgotten by the friends who lament his untimely end.
Dr. Henry Porter was born July 13th, 1832, at Peterborough, in which town his father practised as a surgeon. He received his primary education at the Hereford school under the Rev. Henry Manton, and while yet a school-boy, his interest in Geology having been awakened by the perusal of one of Dr. Mantell's works, he became an enthusiastic collector and student of fossils. On leaving school he spent three years in his father's surgery, and then passed to Queen's College, Birmingham, where he greatly distinguished himself, obtaining a scholarship, two gold medals, and other honours, and becoming at the end of his three years' course of study Warnford's Prize-man. On leaving Birmingham, he continued his studies in London and Paris.
Returning to his native town. Dr. Porter entered on the practice of his profession, devoting his leisure hours to the study of the geology of the district and the formation of a collection of fossils. In 1861 he became a Fellow of this Society, and in the same year published his ' Geology of Peterborough.' This unpretentious but useful little work is an attempt to give in popular language such a sketch of the Geology of a limited district as may be calculated to awaken in residents an interest in our science, and, by furnishing the necessary basis of information, lead the way to further researches. In 1863 Dr. Porter contributed a paper to this Society " On the occurrence of large quantities of Fossil Wood in the Oxford Clay, near
