We have to record the deaths of Dr. William Hankel, Professor of Physics in the University of Leipsic; Prof. F. K. C. L. Büchner, author of the famous book, Force and Matter, at Darmstadt, Germany, May 1st; Dr. Francis W. MacNamara, State Examiner of Medical Stores at the India Office, London, formerly Professor of Chemistry in Calcutta Medical College, and later Chemical Examiner to the Government of India, March 5th, aged sixty-seven years; he was author of a number of books and papers on hygiene and medical chemistry; Jeremiah Head, engineer, President of the Mechanical Science Section of the British Association in 1893, and President of the British Institute of Mechanical Engineers in 1885-'86, March 10th, aged sixty-four years; who was instrumental in introducing into England important American improvements in the manufacture of iron and steel; Franz Ritter von Hanse, Austrian geologist, Intendant of the National Museum in Vienna, Director of the Imperial Geological Survey in 1866, and author of the Geological Map of Austria, Bosnia, and Montenegro, and of geological books, March 20th, aged seventy-seven years; Surveyor Major G. C. Wallich, March 31st, in his eighty-fourth year, and Count Abbé F. Castracan, of Rome, the two oldest Fellows of the Royal Microscopical Society; Dr. P. L. Ryke, of the University of Leyden, aged eighty-six years; Joseph Stevens, honorary curator of the museum at Reading, England, author of archæological and geological papers; Dr. C. Brogniart, entomologist, and author of a memoir On Fossil Insects of the Primary Period, at Paris; Charles L. Prince, author of papers on meteorology and astronomy, at Tunbridge Wells, England, April 22d; Dr. Wilhelm Jordan, Professor of Geometry and Geodesy at the Technical Institution, Hanover, April 17th, aged fifty-seven years; Sir William Roberts, of the Royal College of Physicians, author of lectures and papers on digestion, diet, uric acid, the opium habit in India, etc.; Prof. Karl Scheibler, chemist, at Berlin, aged seventy-two years; Dr. Josef Wastler, docent in geodesy at the Technical Institute in Graz; Dr. H. A. Wahlforso, Professor of Chemistry at Helsingfors, aged sixty years; and Philip Thomas Main, Fellow of St. John's College, Cambridge, England, author of a treatise on astronomy. Transcriber's Notes: Words surrounded by _ are italicized. Words surrounded by = are bold. Obvious printer's errors have been repaired, other inconsistent spellings have been kept, including inconsistent use of hyphen (e.g. "widespread" and "wide-spread"), and proper names (e.g. "Siddânta" and "Siddhânta"). Some illustrations were relocated to correspond to their references in the text. End of the Project Gutenberg EBook of Appletons' Popular Science Monthly, July 1899, by Various