Of the report made in 1849 the American Journal of Science and Arts said: "The geographical survey of Tennessee, under Dr. Troost, is still in progress, and is bringing to light many additions to science, besides developing the various resources of the State. Prof. Troost is well known for his learning, his skill, and his enthusiasm in his investigation, and it is greatly to the honor of Tennessee that such a savant is appreciated and his talents are called into action. In a recent communication from Dr. Troost he mentions that the number of the new genera and species of Crinoideæ which occur in the State of Tennessee is really surprising. His geological report, now before the Legislature of the State of Tennessee, contains a monograph of Crinoideæ in that State, in which sixteen new genera and eighty-eight new species are described, illustrated by two hundred and twenty figures; this number not only surpasses that of those discovered in the other States of the Union, but perhaps is equal to those that have been found over the whole of Europe."
Besides his geological reports of Tennessee, Dr. Troost contributed to the Philadelphia Society for Promoting Agriculture, A Geological Survey of the Environs of Philadelphia, the territory included in which embraced a semicircular area having a radius of fifteen miles from the center at the Rotunda in High Street, and bounded on the east by the Delaware River. A preliminary note described the paper as "an attempt to delineate the geological positions of our environs, and to give some general ideas of the nature and chemical constituents of our soil." Of the pamphlet of forty pages, containing a colored map, ten pages were devoted to the geological survey, fifteen pages to descriptions of soils, and ten pages to their composition. Prof. Troost also published in the Transactions of the Geological Society of Pennsylvania an account of the organic remains and various fossils of Tennessee and adjacent States; in the Bulletin of the Geological Society of France, a memoir on the organic remains and fossils of Tennessee; and in Silliman's American Journal of Science and the Arts, articles on Amber at Cape Sable, Maryland; Minerals of Missouri; Coral Regions of Tennessee; Analysis of a Meteorite from Tennessee; Meteoric Iron from Tennessee and Alabama; A Shower of Red Matter in Tennessee; Three Varieties of Meteoric Iron; Meteoric Iron of Murfreesboro', Tenn.; and Krausite and Cacorene in Tennessee. He translated Humboldt's Aspects of Nature into Dutch. He gathered a collection of about fifteen thousand mineralogical and more than five thousand geological specimens, constituting what was at the time considered the finest cabinet belonging to a single person in the United States. Besides the Philadelphia Academy, he was a member of the
