_ Royal Society. 413 



the connection of the Geodetical Survey of France which had been 

 made by his father, with the corresponding Survey of England which 

 was at that time in progress under General Roy : he was the author 

 likewise of " Memoires pour servir a. l'Histoire des Sciences et a 

 celle de l'Observatoire Royal de Paris, suivis de la Vie de Jaques 

 Dominique Cassini, premier du nom." 



With him have terminated the honours of the house of Cassini, 

 though he was not the last of his race who distinguished himself in 

 the career of the sciences ; his son, Henri Cassini, an upright and 

 enlightened judge in the Cour Royale and the Cour de Cassation, 

 and one of the most learned botanists of his age, fell a victim to the 

 cholera in 1 833, and with him died the last stay of the old age of 

 his father: he was the fifth of his family who had been elected a 

 member of the Academie des Sciences. He was a boy at the break- 

 ing out of the Revolution, and was compelled, from a regard to his 

 personal safety, to live in the strictest retirement at his father's domain 

 of Thury ; a circumstance which turned his attention to the cultiva- 

 tion of Natural History and Botany, and diverted him, as he was 

 accustomed to lament, from those studies and pursuits which formed, 

 as it were, the proper and hereditary honours of his family. 



Theodore de Saussure was born in Geneva the 14th of Octo- 

 ber, 1767. His father, known throughout the civilized world as the 

 geological explorer of the Alps, who first reared observatories on 

 heights almost inaccessible, and who inscribed his name on the 

 eternal snows of the loftiest mountain in Europe, was by profession 

 a physician. Being animated with an ardent love for science, which 

 he cultivated most assiduously, it is not a matter of surprise that after 

 entrusting his son for a short time to a private tutor, he should have 

 undertaken personally his education, so far as to enable him to enter 

 the Academy of Geneva, where young De Saussure soon distin- 

 guished himself. Previously to this period, his father had caused 

 him to study medicine, mineralogy, and natural history ; and had 

 also inspired him with a taste for experimental chemistry, which he 

 constantly required for the analyses of minerals. By degrees the 

 son became associated with the scientific labours of his father, who 

 records that when he resolved upon attempting the ascent of Mont 

 Blanc, in August 1787, his son, then nineteen years of age, expressed 

 the strongest desire to accompany him ; but being apprehensive 

 that he was not sufficiently strong, he was unwillingly obliged to 

 leave him at the Priory at Chamouni, where he made with great 

 care meteorological observations, simultaneously with those carried 

 on at the summit of Mont Blanc. In the month of June of the 

 following year, Theodore de Saussure accompanied his father in 

 the laborious and hazardous expedition to the Col du Geant, where 

 they remained for seventeen days, during which time young De Saus- 

 sure rose every morning at four o'clock, to commence the meteorolo- 

 gical observations, which he continued with unremitting diligence 

 until ten o'clock each night; and so thoroughly did he enter into the 

 scientific pursuits of his parent, that he almost importuned the latter 

 to extend the period of his sojourn amidst those splendid scenes ; 



