224 LIFE AMD LABORS OF HENRY GUSTAVUS MAGNUS. 



Henri Gustave Magnus was born in Berlin, May 2, 1802. He belonged 

 to one of the most honorable families of that city. From bis earliest 

 infancy be mauifested peculiar aptitude for tbe exact sciences and pre- 

 ferred study to the ordinary amusements of cbildbood. He passed 

 tbrougb all tbe grades at tbe academy of Berlin, and received tbe degree 

 of Doctor in 1827. His first researches were made in tbe laboratory of 

 Mitscberlicb ; be next pursued bis studies under Berzelius at Stockholm, 

 where be passed the year 1828. Thence be went to Paris where, in tbe 

 laboratory of Gay Lussac he prepared himself for tbe interesting 

 experiments which he undertook a few years later. Eeturuing to his 

 native city be soon obtained a reputation as an instructor, Avhich be 

 ever after sustained with great distinction and unflagging zeal. He 

 entered upon this career as private tutor ; was nominated in 1831 extra 

 professor, and in 1815 ordinary professor of physics and technology in 

 tbe university of which be became one of the brightest ornaments. He 

 exercised an important influence in developing a taste for the study of 

 physics, as well as in imparting a knowledge of its principles in their 

 most varied applications. For the illustration of tbe subjects of bis 

 lectures he formed the physical cabinet of tbe university, which was 

 enriched after his death by the valuable collection of apparatus belong- 

 ing to himself. 



His first labors were devoted to physical chemistry. In 1825 he con- 

 tributed to this branch of science, through tbe Annales de Foggcndorff, an 

 interesting memoir, on tbe property which iron, cobalt, and nickel, finely 

 divided by a reduction of their oxides in a current of hydrogen, possess 

 of taking fire spontaneously in tbe air at tbe ordinary temperature. He 

 did not confine bimself to tbe mere discovery of the fact, and to show- 

 ing that it w\as an especial attribute of these three metals, but explained 

 it on the principle of De Saussure, of tbe absorption of gas by porous 

 substances, such as charcoal, and by showing that substances of this 

 character, in consequence of their porosity, condense oxygen and enter 

 into combination with it so energetically as to produce incandescence. 



In 1828 he discovered tbe compound which has been called, in com- 

 pliment to him, the green salt of Magnus. This is formed of the ele- 

 ments of chloride of platinum and of ammonia, and was the first of a 

 series of combinations of tbe same substances. In an investigation in 

 common with Ammermiiller, he discovered tbe periodic acid, also the 

 ethionic and istheouic acids, analyzed a large number of minerals, and 

 observed the remarkable pro])erty which certain crystallized silicates 

 possess, of losing by fusion a considerable portion of their weight. 



We cannot stop to enumerate all tbe investigations of Magnus in this 

 branch of science ; we must hasten on to bis numerous and beautiful 

 researches in physics, which constitute bis true claims to renown. These 

 were especially devoted to molecular and calorific phenomena. His first 

 work on physics, entitled "Researches on Capillarity," is rather a study 

 of tbe flow of different gases, through minute cracks in glass vessels. 



