His father, a botanist, was a follower of Jean-Jacques Rousseau. As early as 1805 he had compiled a "Journal of the Weather" and had published his Liber Rerum Naturalium. A year later, inspired by Gall's works, he took up the study of phrenology. The Great Comet of 1811 aroused his interest in astronomy, a science which he continued to pursue, and eight years later, on 3 July, 1819, he himself discovered a new comet. He finally matriculated at Corpus Christi College, Cambridge, in order to study law, but soon abandoned it to study medicine, taking his degree in 1819. Two years before, he had married the daughter of Colonel Beaufoy and taken up his residence at Spa Lodge, Tunbridge Wells. After the birth of his only daughter he moved to Hartwell in Sussex, and then spent three years abroad. His observations and studies in Continental Europe led to the publication, in 1824, of his "Perennial Calendar". It was also during this period that he converted to Catholicism. After his return to England he became a fellow of the Royal Astronomical Society and helped to found a meteorological society, which, however, had but a brief existence.

His father died in 1825, and he soon after took up his residence in Chelmsford in order to be near his daughter, who was a pupil at Newhall Convent. Here he undertook a series of researches on the influence of atmospheric conditions on diseases, and particularly on cholera. In 1830 he collected and published the letters of John Locke, Shaftesbury, and Algernon Sydney. In 1833 he again went abroad, where he spent most of his remaining years, settling finally in Bruges. He continued writing during the latter part of his life, including poetry. He also composed selections for the violin. He numbered among his friends many of the prominent authors and scholars of his time, such as Thomas Gray, Porson, Percy Bysshe Shelley, Peacock, William Herschel, and William Whewell.

Other publications

• Researches About Atmospheric Phenomena (London, 1812; 2nd ed., 1823)
• Reflections on the Destructive Operation of Spirituous Liquors (London, 1812);
• Pocket Encyclopedia of Natural Phenomena (from his father's MSS., 1826);
• Beobachtungen uber den Einfluss des Luftdruckes auf das Gehor (Frankfurt, 1835);
• Observations sur l'influence des Cometes (1836);
• Pan, a Pastoral (Brussels, 1840);
• Essay on Abnormal Affections of the Organs of Sense (Tunbridge Wells, 1841);
• Annales d'un Physicien Voyageur (Bruges, 1848);
• numerous articles in The Gentleman's Magazine.
• A Synoptical Catalogue of British Birds: Intended to Identify the Species Mentioned by Different Names in Several Catalogues Already Extant. Forming a Book of Reference to Observations on British Ornithology Printed by and for Nichols, son, and Bentley, 1817

Sources

• FORSTER, Recueil de ma Vie (Frankfurt, 1835);
• Epistolarium Forsterianum (Bruges, 1845-50);
• BOULGER in Dictionary of National Biography;
• GILLOW, Bibl. Dict. Eng. Cath.