PHYSICS OF THE NINETEENTH CENTURY. LIGHT. 443 



especially by which the distances and heights of inaccessible objects 

 were determined excited his wonder, until he began to see . through 

 the mystery by the aid of an encyclopaedia of mathematics. To use 

 the theodolite now became the boy's outdoor recreation ; to calculate 

 heights and distances from the observed angles his indoor amusement. 

 Between the ages of nine and fourteen Young attended a school at 

 Compton, in Dorsetshire, kept by a Mr. Thompson. Here Greek and 

 Latin were, as usual, subjects to which much time was devoted ; but 

 Young had the opportunity of acquiring from the usher, Josiah Jeffery. 

 some insight into experimental science in his leisure hours. The lin- 

 guistic acquirements which Young of his own accord added to all the 

 ordinary school duties are perfectly amazing. They comprised French, 

 Italian, Hebrew, Persian, and Arabic. His mathematical abilities 

 were no less extraordinary, as may be gathered from the following cir- 

 cumstances. He had taken a great liking to the study of botany, and 

 soon found that, in order to examine the minute organs of plants, a 

 microscope was necessary. He set about constructing one for himself 

 from the mere description of the instrument ; but having met with 

 some mathematical formulae relating to the optical arrangements, in 

 which formulae there occurred certain symbols that he did not under- 

 stand, he actually entered upon the study of the differential calculus, 

 to which these symbols belonged. 



The boy's excessive devotion to severe studies is said to have affected 

 his health, as he was threatened with symptoms of serious disease > 

 but by medical skill and the affectionate care of his friends his health 

 was shortly afterwards restored. Young after this pursued his studies 

 at Youngerbury, in Hertfordshire, under the direction of Mr. David Bar- 

 clay, who afterwards made himself a reputation in classical literature. 

 Dr. Brocklesby, the brother of Young's mother, was at this time one 

 of the most successful physicians in London, and this gentleman had 

 the means of placing his nephew in communication with some of the 

 most influential men of the day. Young's brilliant talents were recog- 

 nized, and had he chosen to enter the arena of public or forensic life, 

 under the patronage of some of the great politicians or statesmen of 

 that time, he would no doubt have had an easy road to the honours 

 which reward success in such a career. His choice was otherwise, for 

 he preferred intellectual freedom to the obligations of political partizan- 

 ship, even though the fetters of the latter might have been forged with 

 golden links. He selected medicine as his profession, and pursued 

 his studies first in London, afterwards at Edinburgh, under Black, 

 Munro, and Gregory. He graduated in medicine at Cambridge Uni- 

 versity also, where he was familiarly known as " Phenomenon Young," 

 and took the degree of M.D. at Gottingen in 1795. Before this Young 

 had become known by his scientific papers on various subjects. A 

 paper by him was published in the " Transactions of the Royal 

 Society " when its author was little more than twenty years of age. It 



