247 



Essay on Chemical Analysis,' 8vo, 1819; the other of * Berzelius' 

 Treatise on the Use of the Blow-pipe,' with additional experiments 

 and notes of his OTvn, Svo, 1822. He was one of the early editors 

 of the Zoological Journal, and a contributor to other learned works. 

 In short, his occupations were many and varied, but they were con- 

 genial to his active mind. His knowledge of Chemistry became a 

 source of profit to him in the year 1824, when the mining companies 

 of South America were desirous of finding some means by which 

 silver might be extracted fi'om its ores without amalgamation. Mr. 

 Children having directed his attention to the subject, succeeded in 

 discovering and perfecting a process by which the silver might be 

 obtained without the use of mercury, and at a less cost. The right 

 of using this process was purchased by several mining companies, 

 and a considerable sum was the fruit of it. 



Mr. Children remained at the British Museum until the death of 

 his wife in 1839, when he sent his resignation to the trustees. He 

 then went to reside with his daughter at Halstead Place, Kent, who 

 had married the only surviving son of the late John Atkins, Esq. 



Although retiring from active life, he was nevertheless constantly 

 employed in scientific researches, and he took up the science of 

 Astronomy with the energy and zeal of a young man. Thus passed 

 the latter years of his life, until with unimpaired faculties the powers 

 of nature gently gave way after the brief illness of a week, and he 

 died on the 1st of January 1852, without the slightest apparent 

 suffering. 



Thomas F. Colby, LL.D., Major-General in the Army, and one 

 of the most distinguished scientific officers of the corps of Royal 

 Engineers, was born at Rochester on the 29th September, 1784, and 

 was the eldest son of Major Thomas Colby of the Royal Marines, an 

 officer who was severely wounded at Lord Howe's battle of the first 

 of June. His grandfather was Mr. Colby of Rhoseygilwin in South 

 Wales, a gentleman of considerable landed property. His maternal 

 uncle was General Hadden, Surveyor- General of the Ordnance. 



The Hfe of General Colby was eminently scientific, and its history 

 will be hereafter embodied in that of the Ordnance Survey. He was 

 however not less distinguished for the genuine simplicity of his cha- 

 racter, his urbanity, his frank but unostentatious hospitality, and his 

 private and domestic virtues, than for his scientific attainments, and 

 the ability and energy he displayed in the performance of his public 

 duties. 



He was educated at Northfieet School under Dr. Crackell ; thence 

 admitted a cadet in the Royal Military Academy ; and in December 

 1801, at the age of little more than seventeen, was promoted 

 to a second lieutenancy in the Royal Engineers. He was early 

 associated with Lieut. -Colonel Mudge (afterwards General Mudge) 

 in the Trigonometrical Survey of Great Britain, that ofiicer having 

 become acquainted with his mathematical acquirements and tastes. 

 In 181 1, was published the third volume of the Survey, which contains 



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