PROCEEDINGS—PERTHSHIRE SOCIETY OF NATURAL SCIENCE. 
XCI 
significance of stratification in rocks. The controversies which arose 
over the Wernerian theories gave rise to the two rival schools known 
respectively as the Neptunists and the Vulcanists, the former giving 
nearly all the credit for the origin of rocks to the agency of water, 
and the latter to that of fire. The first observer to discern the true 
position of each of these agencies in the economy of nature was a 
Scotchman, Dr. James Hutton, who, in 1788, published a treatise in 
the Edinburgh Philosophical Transactions entitled “A Theory of the 
Earth,” which was afterwards enlarged and issued as a separate work 
in 1 7 9 5; 
During this time another observer, William Smith, was quietly 
and laboriously accumulating facts regarding the rocks of England 
and their relation to each other, and, in 1799, he published the first 
tabular record of the various formations in their correct order of 
sequence. 
We have thus reached the very close of the eighteenth century, 
and we see that the ground has been gradually prepared for the 
workers who were to follow. The true history of the rocks had been 
foreshadowed by Pythagoras, it had been suggested afresh by Werner 
and Hutton, and now it remained for the geologists of the nineteenth 
century to build up on that foundation an elaborate superstructure of 
carefully-ascertained facts, and of generalisation deduced from these 
facts. 
We are now in a position to understand the stage which the 
science of geology had reached at the beginning of the year 1801, 
One Hundred years ago. 
At that date, James Hutton had been dead for three years, but 
his friend and biographer, Professor John Playfair, still survived, and 
was busy compiling his “ Illustrations of the Huttonian Theory,” 
which was published two years later, and attracted much more 
attention than the original work had done. A young Scotch student, 
Robert Jameson, then 26 years of age, had recently returned from 
Freiberg, in Saxony, where he had been studying geology under 
Werner, and four years later he was appointed to the Chair of 
Natural History in Edinburgh. Sir James Hall, who had assisted 
Hutton by his experiments on igneous rocks, was still in the prime of 
life, being then 39 years of age. In England, William Smith, who was 
31 years of age, was hard at work compiling the first Geological Map 
of England, which was published fifteen years later. As yet there 
were no Geological Surveys at work, and no Geological Societies had 
been founded, but seven years later the Geological Society of London 
was inaugurated. In Paris, Baron Cuvier, the great naturalist, was 
examining and comparing the fossil animals which he found in the 
rocks of the Paris Basin, and restoring their original forms. 
This exhausts the list of the more eminent geologists who were 
actively at work at the commencement of the century. Several 
others who were to leave their names on the new century’s roll of 
fame were yet in infancy or early youth. Charles W. Peach was one 
year old; Charles Lyell and John Anderson, father of the late 
Minister of Kinnoull, were both three; Roderick Murchison was 
eight; Adam Sedgwick, thirteen; William Buckland, sixteen; and 
