LOCKE
105
LOCKE
time Health Officer of the Port of
Philadelphia. He never married, and
died on September 26, 1756, while
paying a professional call.
Dr. John Jones, who had been his pupil, wrote of him as " A person whose whole life had been one continued scene of benevolence and humanity."
F. R. P.
Locke, John (1792-1856),
John Locke was born in Lempster, New Hampshire, February 19, 1792, the son of Samuel Barron and Hannah (Pussell) Locke; and in 1796 his father moved to Bethel, Maine.
Young Locke's mechanical taste and ingenuity, as well as his love for books, was manifested at an early age, botany being his favorite study, but this he pursued under great difficulties. The books available were the "Pentandria" — the fifth class of plants in the Linnean system — and a small work by Miss Wakefield. In 1816 he met Dr. Solon Smith of Hanover and with him spent two years in further study of botany, while studying medicine also. Before graduating he obtained the position of assistant surgeon in the navy, but after a short and disastrous voyage, resigned and returned to medicine. Although he had never seen a piece of chemical apparatus, his genius led him to construct his own instruments. Chiseling out a mould in a soft brick he made twenty plates of zinc the size of a silver dollar. With as many silver dollars, and cloths wet in brine, he constructed a " Volta's pile" which was a partial success.
He received his M. D., from Yale College in 1818, and that year deliver- ed his first public lectures in Portland, Maine, also in Boston, Salem, and Dartmouth College.
After graduation he l)egan practice, but abandoned it, not from want of patients, but from their neglect to pay. Discouraged, he accepted a position as assistant in a Female Academy in Windsor, Vermont.
In June, 1821, he went West and
estabHshed a school for girls in Lex-
ington, Kentucky, in 1822 going to
Cincinnati, Ohio, where he found a
friend, one Ethan Stone, who intro-
duced him to a number of the most
influential citizens, with whose as-
sistance he established a school for
girls which soon became popular, even
famous. Dr. Locke's method of in-
struction was largely conversational.
In 1835 he was elected professor of chemistry in the Medical College of Ohio liut found the place wanting in the necessary means of illustration, so, to meet every possible demand, he visited Europe, and purchased many thousand dollars worth of apparatus. Dr. Locke held this position until the session of 1849-50, when he was dis- placed, but at the solicitation of friends he resumed and held the chair until 1853. In 1854 he accepted the position of principal in the academy at Lebanon, Ohio. The following year he returned to Cincinnati.
He had a most accurate knowledge of geolog}', and in 1838 was engaged in a state geological survey of Ohio. His report on the " (ieological Struc- ture of the Southwestern Portion of the State," being regarded as a paper of greatest value. Later he was, in connection with David D. Owen, call- ed into the service of the United States, for the survej' of the mineral lands of the Northwest, and during his survey his familiarity with electricity and magnetism was very useful in indicat- ing the depth and course of veins of ore.
Dr. Locke invented a number of scientific instruments; among them the thermoscopic galvanometer described in the "American Journal of Sciences," vol. xxxiii. The object was, "to construct a thermoscope so large that its indications might be seen on the lecture table, and at the same time so delicate as to show extremely small changes of tem- perature," and in volume xxiii of the "American Journal of Sciences" is
