2i6 GREAT MEN OF SCIENCE 



water, resin, clay, and stone, when they are placed between 

 the conductor and the magnetic needle. The needle could 

 be placed without change in the eflPect in a brass box, and 

 this could be filled with water. Needles of brass, glass, resin, 

 and other substances, when suspended so as to be capable 

 of motion like a magnetic needle, remained uninfluenced. 



A short description in Latin of all these and other ex- 

 periments was sent by Oersted at the end of July 1820 to 

 many learned societies, single individuals, and periodicals. 

 The discovery thus very quickly became generally known. 

 It produced just as much general astonishment as Volta's 

 pile twenty years previously, and though at the time the as- 

 tonishment was somewhat superficial, the subsequent history 

 up to to-day has shown that almost everything founded and 

 achieved from then on by scientific research and technology 

 has come to us from Volta's pile by way of Oersted's dis- 

 covery, with the sole exception of the series of ideas derived 

 from Rumford, Carnot, and Robert Mayer, which attacked 

 the study of nature at another point, and went still more 

 deeply. 



Oersted was born on the island of Langeland, where his 

 father was an apothecary. ^ His family circumstances were 

 not prosperous, for which reason little could be spent on 

 schooling. However, Hans Christian taught himself arith- 

 metic from an old schoolbook, and also much else by an ex- 

 change of ideas with his brother, who was a little younger 

 than himself, and by the occasional help of private teachers. 

 At the age of twelve his father took him to assist in the shop, 

 where he soon found great pleasure in chemical work. For 

 this reason he was very anxious to go to the University, and 

 entered for the matriculation examination, which he and 

 also his brother succeeded in passing. At the age of seven- 

 teen he went to Copenhagen, where his studies - combined 



^ Oersted's life is described in a preface to a translation of his book The 

 Soul in Nature, by L. and J. B. Horner, London, 1852. 



