began experimenting on the preparation of oil from lard. He placed the lard in a canvas bag and suspended it in a warm room, thus obtaining by the slow process of dripping an oil that the family used in lamps. An account of these experiments was published, and is believed to have been the starting point of the production of lard oil, which has since become so extensive.
About the time the field work of the New York survey was finished, Prof. Mather became Professor of Natural Science in the Ohio University at Athens. He held this position from 1842 to 1845 and from 1847 to 1850, being vice-president and acting president in 1845. The period from 1845 to 1847 was occupied in examining mineral lands for mining companies, mainly about Lake Superior, but also in New Jersey, Virginia, and Massachusetts. During the first quarter of 1846 he was acting Professor of Chemistry and Geology in Marietta College, his other engagements making him unwilling to accept the professorship. In the winter of 1845 he began a series of experiments on the extraction of bromine from the bitter waters of the salt works near Athens, Ohio. At that time bromine, which can now be had for sixty cents a pound, was selling at sixteen dollars an ounce. The results of his investigations were published in the American Journal of Science. They showed that bromine could be obtained from these waters for much less than it was then costing, and resulted in the establishment of a plant at Pomeroy, Ohio, which produces the greater part of the world's present supply of this substance.
In similar public and private employments the rest of his life was passed. He was Agricultural Chemist for the State of Ohio, and Secretary of the State Board of Agriculture from 1850 to 1854. During part of this time he edited the Western Agriculturist, and during the last year was member for Ohio of the United States Board of Agriculture. He also continued to make examinations of mineral lands. His first wife having died, he married in 1851 Mrs. Mary (Harries) Curtis, who survived him. By this marriage he had one son. The person of Prof. Mather was large and robust, and he had a great capacity for physical and mental labor. He died February 26, 1859, in Columbus, Ohio, at the age of fifty-four. His death was sudden, and was ascribed to a complication of dropsy and paralysis.
In addition to his writings already mentioned. Prof. Mather contributed frequent papers to the American Journal of Science and other scientific periodicals, and he wrote many reports on the explorations made in the course of his professional work. He received the degree of LL. D. from Brown University in 1855, was a member of twenty-five scientific and literary organizations, a life-member of many religious associations, and for fifteen years a trustee of Granville College.