In 1821, being appointed professor at Dartmouth, Dr. Dana removed to Hanover, where, relinquishing the practice of medicine, he devoted his whole attention to his favorite studies, to which was now added Botany, upon which he delivered some courses of lectures.
Dr. Perkins, the Professor of Materia Medica, removed to New York after the dissolution of the "University of New Hampshire," and the late admired and lamented Dr. Daniel Oliver, of Salem, was appointed to the professorship. Dr. Mussey, celebrated for his surgical knowledge and skill, remained as the head of the Medical School, and among these gentlemen, differing widely as they did in many characteristics, the warmest friendship subsisted. During the intervals of leisure from strictly professional duties, Dr. Dana occupied himself in continuing to write for "Silliman's Journal," and in frequent excursions to various parts of New Hampshire, for the purpose of analyzing the ores and waters of mines and springs. His published analysis of the waters of a spring in Burton, N. H., was considered so scientific a production, that he was written to as to accepting a professorship in the University of Virginia. Not wishing the appointment, he declined becoming a candidate.
In the latter part of 1825, Professor Dana published "An Epitome of Chemical Philosophy," designed as a text-book for his own classes, but which was afterwards adopted as such in two other institutions. In 1826, he was appointed one of the visitors of West Point Military Academy, and soon after his return was chosen to the chair of Chemistry, in the College of Physicians and Surgeons in the University of New York, to which city he then removed. He was elected member of the Linnæan Society of New York, and accepted an invitation to deliver a course of lectures before the Athenæeum.
During his residence at Hanover, Professor Dana had been much interested in Electro-magnetism, then a new science, and in preparing apparatus for exhibiting its wonders, freely stating his conviction that it would produce more astonishing results than any power previously known. When surprise was expressed at his selecting for his Athenæeum lectures this subject, so little known even in Europe, and in which so few in this country would feel any interest, Dr. Dana replied that he had chosen it for those reasons; that he thought it time for public attention to be directed to it, as he was certain it would lead to most valuable results, and that he should endeavor to render it popular. How far he succeeded, the delighted audiences that crowded to hear him bore evidence. Of the truth of his prediction as to the results to be wrought out by the science, the marvels of the electro-magnetic telegraph bear witness to the world.
Samuel F. B. Morse was then following his profession as a painter in New York, and lectured upon art before the Athenæeum. An intimacy sprang up between him and Dr. Dana, whose lectures he attended, and whom he used to visit in his laboratory, thus becoming familiar with his views on scientific subjects. Morse's published statements as to the origin of his knowledge of electro-magnetism are as follows:
"I learned from Professor Dana, in 1827, the rationale of the electro-magnet, which' latter was exhibited in action. I witnessed the effects of the conjunctive wires in the different forms described in his lectures, and exhibited to his audience. The electro-magnet was put in action by an intensity battery; it was made to sustain the weight of its armature, when the conjunctive wire was connected with the poles of the battery or the circuit was closed; and it was made to 'drop its load' upon opening the circuit. These, with many other principles of electro-magnetism were all illustrated experimentally to his audience. These being the facts, to whom do I owe the first knowledge which I obtained of the science of electro-magnetism bearing upon the practical development of the telegraph? Professor Dana had publicly demonstrated in my hearing and to my sight all the facts necessary to be known respecting the electro-magnet.... The volute modification of the helix to show the concentration of magnetism at its centre, adapted to the electric magnet, the modification since universally adopted in the construction of the electro-magnet, is justly due, I think, to the inventive mind of Prof. James Freeman Dana. Death, in striking him down at the threshold of his fame, not only extinguished a brilliant light in science—one which gave the highest promise of future distinction—but the suddenness of the stroke put to peril the just credit due him for discoveries he had already made. Dana had not only mastered all of the science of electro-magnetism then given to the world, a science in which he was an enthusiast, but, standing on the confines that separate the known from the unknown, was at the time of his decease preparing for new explorations and new discoveries. I could not mention his name in this connection without at least rendering this slight but inadequate homage to one of the most liberal of men and amiable of friends, as well as promising philosophers of his age."
The delivery of these lectures was amongst Dr. Dana's last public efforts. A severe cold, resulting in an attack of erysipelas affecting the brain, terminated his brief life of thirty-three years, on the 15th of April, 1827.
In the various relations of private life he had won the warm attachment of all who knew him. To the charm of a buoyant and affectionate disposition he added Christian principle and character. During his student life at Harvard, he had become a communicant of the Episcopal Church, and continued a devout worshipper according to her liturgy. Her Burial Service was read over his remains, by his friend Dr. Wainwright, the funeral rites being performed at Grace Church, on the 17th of April.
When it was proposed, in 1871, by the National Telegraph Monument Association to erect a monument to Professor Morse, at Washington, the family of Dr. Dana furnished, at its request, a portrait of him from which a likeness was to be cast for one of the faces at the base of the monument. Since the death of Professor Morse, no progress seems to have been made in the effort to erect this memorial of scientific progress.