116 
MOUNTAINS AND THEIR ORIGIN. 
and cracks so formed. Thus he saw igneous 
rocks not only covering or underlying stratified 
deposits, hut penetrating deep into their struc- 
ture, forming dikes at right angles with them, 
and presenting, in short, all the phenomena be- 
longing to volcanic rocks in contact with strati- 
fied materials. He again pushed his theory too 
far, and, inferring from the phenomena immedi- 
ately about him that heat had been the chief 
agent in the formation of the earth’s crust, he 
was inclined to believe that the stratified mate- 
rials also were in part at least due to this cause. 
I have alluded in a former number to the hot dis- 
putes and long-contested battles of geologists 
upon this point. It was a pupil of Werner’s who 
at last set at rest this much vexed question. 
At the age of sixteen, in the year 1790, Leo- 
pold von Bucli was placed under Werner’s care 
at the mining school of Freiberg. Werner found 
him a pupil after his own heart. Warmly adopt- 
ing his teacher’s theory, he pursued his geologi- 
cal studies with the greatest ardor, and continued 
for some time under the immediate influence and 
guidance of the Freiberg professor. His univer- 
sity si udies over, however, he began to pursue his 
investigations independently, and his geological 
excursions led him into Italy, where his confi- 
dence in the truth of Werner’s theory began to 
be shaken. A subsequent visit to the region of 
