THE hundredth anniversary of the invention of the voltaic or electric pile is to be celebrated in 1899 at Como, the birthplace of Alexander Volta, by an international electrical exhibition. A national exhibition of the manufacture of silk--machinery, preparation, and processes--will be held in connection with it. An international congress will also be held for the discussion of the progress and applications of electricity. A PRIZE of five hundred guineas is offered by the Sulphate of Ammonia Committee, 4 Fenchurch Avenue, London, for the best essay on The Utility of Sulphate of Ammonia in Agriculture; the committee to have entire disposal of the selected essay, and the refusal of any of the others for not more than fifty guineas each. The essays--in English--should be in the hands of the committee not later than November 15, 1898. RECENT death lists include the names, among men known to science, of Prof. Park Merrill, chief of the Forecast Division of the Weather Bureau, at Washington, August 8th; Dr. E. V. Aveling, late assistant in physiology at Cambridge and professor of chemistry and physiology at New College, a writer upon scientific topics, in London, August 4th, aged forty-seven years; M. Paul Sevret, mathematician and member of the French Academy of Sciences, in Paris, June 24th, aged seventy years; W. F. R. Surringer, professor of botany in the University of Leyden, and director of the Botanical Garden and Herbarium; J. A. R. Newlands, the discoverer of the periodic law of the chemical elements, in Lower Clapton, London, July 29th, aged sixty-nine years; the astronomer Romberg, who succeeded Encke at Berlin in 1864, and was called to Pulkova in 1873, author of numerous papers in Monthly Notices on double stars and planetary and cometary observations, at Pulkova, July 6th, aged sixty-four years; John Hopkinson, an eminent British electrician, president of the Institute of Electrical Engineers in 1890 and 1896, killed with his three children in an attempt to ascend the Dent de Visivi, Alps, August 24th; Dr. H. Trimble, professor of practical chemistry in the Philadelphia College of Pharmacy, and editor of the American Journal of Pharmacy; M. de Windt, geologist of the Belgian Exploring Expedition to the Congo, drowned in Lake Tanganyika, Africa, August 9th; Dr. Paul Glan, assistant professor of physics in the University of Berlin, aged fifty-eight years; Dr. E. J. Bonsdorf, formerly professor of anatomy and physiology at Helsingfors, Finland, aged eighty-eight years; Dr. Robert Zimmerman, formerly professor of philosophy in the University of Vienna, at Salzburg, Austria, aged seventy-seven years; M. J. M. Moniz, known by his investigations of the natural history of Madeira, at Madeira, July 11th, aged sixty-six years; and M. Pomel, a distinguished French mining engineer, professor of geology and past director at the Algiers Scientific School, and author of a number of special works, at Oran, Algeria.