242 JOHN TYNDALL 
their dominant tastes were already shown. As a boy, 
Spencer was deeply interested in the rearing of in- 
sects and studying their transformations, while he 
also achieved no mean proficiency as a_ botanist. 
Tyndall, on the other hand, was from the first very 
much absorbed in molecular physics. The dance of 
molecules and atoms, in its varied figures, had an 
irresistible attraction for him. In 1848, after giving 
up his position as a civil engineer, he went to the 
University of Marburg, where he received a doctor’s 
degree in 1851. His work at the university consisted 
chiefly of original investigations on the relations of 
magnetism and diamagnetism to molecular arrange- 
ment. It resulted in a paper published in the PAz?- 
osophical Magazine in 1850, which at onge made 
Tyndall famous. It showed the qualities for which 
his work was ever afterward distinguished. As Hux- 
ley says of him: “ That which he knew, he knew 
thoroughly, had turned over on all sides, and probed 
through and through. Whatever subject he took up, 
he never rested till he had attained a clear conception 
of all the conditions and processes involved, or had 
satisfied himself that it was not attainable. And in 
dealing with physical problems, I really think that he, 
in a manner, saw the atoms and molecules, and ‘felt 
their pushes and pulls.’” 
When, after a further year of work at the University 
of Berlin, Tyndall returned to England, he was at once 
elected a Fellow of the Royal oF and one of the 
secretaries of the physical section of the British Asso- 
ciation, distinguished honours for a young man of two- 
and-thirty. In the following year he was appointed 
Fullerian Professor of Physics in the Royal Institution. 
