REMSEN, Ira, chemist, born in New York city, 10 February, 1846. He studied at the College of the city of New York, and was graduated at the College of physicians and surgeons of Columbia in 1867. Selecting chemistry as his profession, he went to Munich, where he spent a year, and then to Gottingen, where he received the degree of Ph.D. in 1870. Dr. Remsen then went to Tubingen at the invitation of Professor Rudolph Fittig, and continued as assistant in the laboratory of that university for two years. In 1872 he returned to the United States, and accepted the professorship of chemistry and physics at Williams. At that time there was no chemical laboratory in the college, but in the course of a year facilities were obtained and investigations on the action of ozone on carbon monoxide, on phosphorus trichloride, and researches on parasulphobenzoic acid were completed. In 1876 he was called to fill the chair of chemistry in Johns Hopkins university, then just founded, and since, with facilities that are unexcelled in the United States, he has carried on, without interruption, systematic scientific researches. Among these are studies on "The Oxidation of Substitution-Products of Aromatic Hydrocarbons" that have led to results of special interest ; researches "' On the Relations between Oxygen, Ozone, and Active Oxygen"" an investigation " On the Chemical Action in a Magnetic Field," in which positive evidence is furnished for the first time that in some eases chemical action is influenced by magnetism" and studies "On the Sulphinides," a new class of organic compounds, some of which have remarkable properties. One, discovered in his laboratory, has come into prominence under the name of saccharine. It is about 250 times sweeter than ordinary sugar, and is not injurious in its action upon the sys-tern. Another substance, belonging to the same class as saccharine, is fully as sweet, another is intensely bitter, and two others have been investigated, each of which tastes sweet when applied to the tip of the tongue, and bitter at the base of the tongue. The results of other investigations are given in papers "On a New Class of Coloring Matters known as Sulphon-Fluoresceins," "On the Decomposition of Diazo-Compounds by Alcohol," and "On the Relative Stability of Analogous Haloten Substitution-Products." hi 1881 he was invited by the city council of Boston to look into a peculiar condition of the city water, which was unfit for use, owing to a disagreeable taste and odor Dr. Remsen showed that the trouble was due to a large quantity of fresh-water sponge in one of the artificial lakes from which the water was drawn He has also been intrusted with special researches by the National board of health, among which were "An Investigation of the Organic Matter in the Air" and " On the Contamination of Air in Rooms heated by Hot-Air Furnaces or by Cast-Iron Stoves." He is a member of scientific societies at home and abroad, and in 1882 was elected to the National academy of sciences, on whose committees ha has served, notably on the one that investigated the glucose industry of the United States (1884), and he was chairman of the committee to consider the practicability of a plan to relieve manufacturers from the tax on alcohol by adding to it wood spirits, with the object of making it unfit for use as a beverage. In 1879 he founded the "American Chemical Journal," and he has since edited that periodical, in which his papers have appeared. He has published a translation of Fittig's "Organic Chemistry" (Philadelphia, 1873); "The Principles of Theoretical Chemistry" (1877" enlarged ed., 1887), of which English and German editions have appeared. "Introduction to the Study of the Compounds of Carbon, or Organic Chemistry" (1885), of which English, German, and Italian editions have been published Introduction to the Study of Chemistry" (New York, 1886), of which English and German editions were made; and "The Elements of Chemistry" (1887).