During the next three years they kept up and increased their knowledge of chemistry by repeating the experiments of Dr. Ure's course. Desiring to extend his knowledge of chemistry and geology, David Dale Owen in 1831 returned to Great Britain. He had as a companion Henry D. Rogers, and they both lived at the house of Owen's father in London while attending the lectures of Dr. Turner at the London University.
After about a year abroad Owen came back to the United States. Soon after his return he was stricken with Asiatic cholera, which was epidemic in this country in the summer and fall of 1832, but was fortunate enough to survive the attack. Wishing to increase his knowledge of anatomy and physiology as an aid in the study of paleontology, he entered the Ohio Medical College, in Cincinnati, and was graduated in the spring of 1836. He devoted the summer following his graduation to gaining practical experience in field geology. To this end he accompanied at his own expense Dr. Gerard Troost, who was then engaged on the State Survey of Tennessee.
Dr. Owen married, March 23, 1837, Caroline C. Neef, the third daughter of that pioneer of Pestalozzian education in America, Joseph Neef.
Dr. Owen had been appointed State Geologist of Indiana and immediately after his marriage he entered upon the duties of this position. He made a preliminary reconnoissance in 1837 and 1838, his report upon which was published immediately after its completion and reissued in 1859. Geological science being little understood in the West when this document first appeared, a brief introductory exposition of the leading formations was given in it, after which the rich deposits of coal, iron, and building stones within the limits of the State were described.
The Hon. James Whitcomb, then Governor of Indiana, was soon afterward appointed Commissioner of the General Land Office, and Congress having ordered a survey of the Dubuque and Mineral Point districts under the direction of his bureau, he selected Dr. Owen, with whose ability he was well acquainted, to conduct this examination. These districts comprised eleven thousand square miles of the Northwest Territory, now included in the States of Wisconsin and Iowa, and the object of the examination was to enable the commissioner to reserve from sale those sections found to contain mineral wealth. But a short time was allowed for the work, hence it became necessary to organize a large force. The difficulties involved in such a rapid prosecution of the survey are indicated in the report presented by Dr. Owen to the commissioner, April 2, 1840. "In one month from the day I received my commission and instructions," he says, "(to wit, on September 17th), I had reached the mouth of Rock River; engaged one hun-
