experiments and the extent and variety of the apparatus he employed. He spared no labor or expense in his operations, and, being a handy mechanician, he was able to bestow much ingenuity in the construction of novel devices for experiment and illustration. He accumulated instruments and material with astonishing profusion. To these he added graphic illustrations and lucid descriptions to make his lectures intelligible and interesting. When he resigned his professorship, he gave all the apparatus he had accumulated to the Smithsonian Institution.
He was a man of literary tastes, fond of poetry, and himself wrote verses occasionally. He also sometimes wrote articles on the political and financial questions of the day, and contributed moral essays to the Portfolio, under the signature of "Eldred Grayson."
In person he had a robust frame, a large head, and an imposing figure and presence.
In his family and among his friends, according to Prof. Silliman, he was very kind, and his feelings were generous, amiable, and genial; yet, in the absence of mind occasioned by his habitual abstraction, and when absorbed in thought, his manner was occasionally abrupt. With his keen and active mind, conversation would sometimes seem to awaken him from an intellectual reverie. He had great colloquial powers, but to give them full effect it was necessary that they should be aroused by a great and interesting subject, and the effect was heightened by the injection of antagonism. He would then discourse with commanding ability, and his hearers were generally as ready to listen as he to speak. He was a man of unbounded rectitude, a faithful friend, and a lover of his country and its best interests, without thought of personal emolument or political advancement. He was a voluminous scientific writer. For many years his contributions to the American Journal of Science were more numerous than those of any other correspondent. The full list of them includes about one hundred and fifty articles, in forty-eight volumes of that journal, the record of the titles of which occupies five columns in the General Index of the first fifty volumes. Besides notices of the various substances he discovered or experimented with, and descriptions of apparatus, we find among these articles some that touch the principles of chemical and physical philosophy—as on the nature of acids and salts; concerning Faraday's views on atoms; on chemical nomenclature, a subject which is also discussed in a letter to Berzelius; on some inferences from the phenomena of the spark in Thompson's work on heat and electricity; on the error that electric machines must communicate with the earth; on a new theory of galvanism; on the cause of heat: a reply to Prof. D. Olmsted's views on the materiality of heat;