LYONS (IsaAEL), a good mathemati cian and botanist, was the son of a Polish Jew, silversmith, and teacher of Hebrew at Cambridge, in England, where he was come to settle, and where young Lyons was born, 1739. He was a very extraor dinary young man for parts and ingenui ty ; and showed very early in life a great inclination to learning, particularly in ma thematics, on which account he was much patronised by Dr. Smith, master of Trini ty College. About 1755 he began to study botany, which he continued occa sionally till his death ; in which he made a considerable progress, and could re member not only the Linnman names of almost all the English plants, hut even the synonyma of the old and he had prepared large materials for a Flora Cantabrigiensis, describing fully every part of each plant from the speci men, without being obliged to consult, or being liable to be misled, by former au thors.
In 1758, he obtained much celebrity, by publishing " A Treatise on Fluxions," dedicated to his patron Dr. Smith ; and in 1763, " Fasciculus Plantarum circa Can tabrigiam," &c. in the same year, or the year before, he read lectures on botany at Oxford with great applause, to at least sixty pupils ; but he could not be prevail ed on to make a long absence from Cam bridge.
Mr. Lyons was some time employed as one of the computers of the nautical al manac; and besides lie received frequent other presents from the Board of Longi tude for his own inventions, He had studied the English history, and could quote whole passages from the monkish writers verbatim. He could read Latin and French with ease, but wrote the for mer ill. He was appointed by the Board of Longitude to sail with Captain Phipps, in his voyage towards the north pule, in 1773, as astronomical observator; and he discharged that office to the satis faction of his employers. After his return
from this voyage he married, and settled in London, where he died of the measles in about two years.
At the time of his death he was en gaged in preparing for the press a corn• plete edition of all the works of the late learned Dr. Halley, a work very much wanted. His calculations in " Spherical Trigonometry abridged," were printed in the Philos. Trans. vol. lxv. for the year 1775, page 470. After his death, his name appeared in the title-page of a Geo graphical Dictionary, the astronomical parts of which were said to be " taken from the papers of the late Mr. Israel Lyons of Cambridge, author of several valuable mathematical productions, and astronomer in Lord Mulgrave's voyage to the northern hemisphere." The astrono mical and other mathematical calcula tions, printed in the account of Captain Phipps's voyage towards the north pole, mentioned above, were made by Mr. Lyons. This appeared afterwards, by the acknowledgment of Captain Phipps, when Dr. Horsley detected a material er ror, in some part of them, in his "Re marks on the Observations made in the late Voyage, &c." 1774.
" The Scholar's Instructor, or Hebrew Grammar, by Israel Lyons, teacher of the Hebrew tongue in the university of Cambridge," the 2d edition, &c. 1757, 8vo. ; was the production of his father, as was also another treatise, printed at the Cambridge press, under the title of " Observations and Inquiries relating to various parts of Scripture History," 1761.