fessorship of Chemistry and Natural Science at Troy. After a second visit to Europe, he made a tour of geological study in the Southern States in the spring of 1860. In the next year he traveled through Ireland, Scotland, Holland, Belgium, and a part of Germany, and spent a semester in Göttingen in the study of geology and mineralogy, under Walterhausen. He then visited and studied the volcanic regions of Italy, ascended Mount Vesuvius, explored the regions of the solfatara, climbed Mount Etna, examined the glaciers of Switzerland and the configuration of the Alpine regions; and, in France, inspected the natural curiosities of the Puy-de-Dôme. In 1872 and 1875 he made three visits to California, in the course of which he traveled in Nevada and Idaho, and the mining regions of Colorado and Utah, and included in his third trip the Yosemite Valley. He spent the summer of 1877 in northern Europe—Finland and Russia—when he enjoyed as a privilege the traversing of the fields which Linnæus had explored for material for his great botanical work. In the next year he was appointed by President Hayes juror for the United States at the Paris Exposition, and was assigned to the department of mineralogy. Having engaged, in 1880, in the service of an oil company as chemical adviser and expert, he has since devoted much time and attention to the refining of petroleum, methods of testing, and the composition and analysis of crude oils. In the course of these investigations he has been able to throw considerable light on the important subject of the prevention of the nuisances arising from the processes of treating petroleum. In 1881 the New York State Board of Health selected him to be inspector of petroleum-oils, and appointed him a commissioner to London to consider methods of dealing with petroleum nuisances. Another visit to northern Europe, in the summer of 1884, embraced the fiords and glaciers of Norway, and was extended to the North Cape.
Professor Nason's published works include an "Inaugural Dissertation on the Formation of Ether" (1857); "Table of Reactions for Qualitative Analysis" (1865); a translation and revision of Wöhler's "Hand-Book of Mineral Analysis" (1868); "Table for Qualitative Analysis in Colors" (1870); an edition of Elderhorst's "Manual of Blowpipe Analysis" (1873, followed by fourth and fifth editions in 1875 and 1876); an edition of the "Manual of Blowpipe Analysis and Determinative Mineralogy" (1880); and a semi-centennial catalogue, the "Proceedings of the Semi-Centennial Celebration," and a "Biographical Record" of Rensselaer Polytechnic Institution. Besides receiving numerous college and university honors, Professor Nason has been elected Fellow of the American Association for the Advancement of Science; Fellow of the London Chemical Society, and of the Society of Chemical Industry; member of the American Chemical Society, of the New York Academy of Sciences, of the American Institute of Mining Engineers, of the Troy Scientific Association; an honorary mem-
