for them, and was the first American student who visited Germany for that purpose. He spent the year 1833 in Wöhler's private laboratory in Cassel; then practiced for nine months in the laboratory of Prof. Gustav Magnus, in Berlin; and employed the rest of three years abroad in attending lectures in Berlin and Vienna, and in visiting manufacturing establishments on the Continent and in England.
Having returned home, Mr. Booth established, in 1836, a student's laboratory—"the parent of all our existing laboratories for students in applied chemistry"—and became a teacher, "But it was no part of Mr. Booth's idea," Mr. Dubois says, "to make the laboratory course usurp the rightful position of the text-book and the lecture. He saw the great want of a supplementer rather than a supplanter. How truly he discerned what the scientific as well as the commercial world required, and how fully he met that requirement, needs no explanation here. The student's laboratories all over the country—if not beyond—as well as the throng of students who have come into and gone from his own laboratory during the past half-century—all attest the foresight, the judgment, the energy of a scientist and a business man."
In 1836 Mr. Booth was appointed Professor of Chemistry applied to the Fine Arts, in the Franklin Institute. In this capacity he delivered, between 1836 and 1845, three courses of lectures, of three seasons to each course. From 1842 to 1845 he was also Professor of Chemistry in the Central High School of Philadelphia. He interested himself in mineralogy and geology, and engaged in the Geological Surveys of Pennsylvania and Delaware, concerning which Prof. J. P. Lesley has written: "Prof. Booth and John Frazer, then a young man, were appointed by Prof. Rogers, in the spring of 1836, his two assistants in prosecuting the work of the first Geological Survey of Pennsylvania, From spring to fall they traveled along the Susquehanna and Juniata Valleys, blocking out the order of the great formations. Prof. Booth was sent by Prof. Rogers up the Potomac to make a section which could be compared with the Juniata section; and, when these three met at Huntingdon, he announced, to the astonishment of Mr. Rogers, that the mountains which fill the middle belt of Pennsylvania were made by two separate formations, now known as No. IV and No. X. Mr. Rogers was unwilling to accept this conclusion, and instructed Mr. Frazer to go to the Huntingdon Bedford line and make a cross-section from the Broad-Top coal down to the limestone of Morrison's Cove. At the end of the week the three met again in Huntingdon, and Mr. Frazer confirmed the statement of Prof. Booth. Mr. Rogers was still dissatisfied, and then went himself to repeat the section made by Mr. Frazer, finding it correct, and then accepting Prof. Booth's
