HASSELQUIST, FREDERIC, a Swedish naturalist, and one of the most distinguished of all Linnæus' pupils, was born in 1722, at Taern-Valla, in E. Gothland. His father, who was vicar of the parish, died, leaving his family quite unprovided for; but a kind uncle had the young Hasselquist educated with his own children. After the death of this good friend, he was sent in 1741 to the university of Upsal, where his taste for the study of nature was fostered and developed by Linnæus. In 1747 he published an essay, De Viribus Plantarum, in which with equal boldness and ability he exposed the popular ideas of the medical virtues of many plants, and defended the old but then discarded doctrine of "like forms, like virtues." It is to this defence of Hasselquist's that the doctrine in question mainly owes the steady foot-hold it has ever since his day maintained. His scientific abilities, backed by the influence of Linnæus, now procured for him one of the scholarships for enabling students to travel, and Hasselquist set out for the Holy Land, the natural history of which was at that time very imperfectly known. After visiting part of Asia Minor, Egypt, and Palestine, he turned his face in the direction of home; but his constitution, naturally weak, gave way under the fatigues and anxieties of travel, and he died at Smyrna, Feb. 9, 1752, at the early age of thirty. His collections reached home in safety, and, five years after his death, the results of his wanderings in the east were published by Linnæus under the title of Iter Palestinum, a work which contains a world of information on almost every department of the natural history of the countries visited by Hasselquist, and which has not even yet been superseded as a book of reference. The work is divided into two parts, the first consisting of the traveller's journal and letters, and the second of his remarks on the botany, zoology, and mineralogy of the countries he passed through, with observations on the prevalent diseases and their cure, and the state of industry, commerce, and the arts. The amount of genuine and solid labour and ability displayed in this work will prevent it from ever being totally superseded. Its author's name is consecrated in his favourite science by having been given to the Hasselquistia cordata, an oriental umbelliferous plant of the order of Apinaceæ. His travels were translated into English in 1766.