XC PROCEEDINGS—PERTHSHIRE SOCIETY OF NATURAL SCIENCE. 
accomplish in the way of discovery or generalisation, the ground has 
been prepared for them by those who have gone before,—both by 
those whose names are written in the roll of fame, and also by those 
more obscure workers who have accumulated the necessary store of 
facts, but whose names have been forgotten. 
Passing from these more general considerations, let us glance 
very briefly at the development which has taken place during the 
nineteenth century and the Queen’s reign in the science which I 
have chosen for consideration to-night, namely, Geology, or, in other 
words, in regard to our knowledge of the structure and history of the 
Earth’s crust. Perhaps the best way to realise the progress which 
geology has made during the century which has just closed will be to 
try to picture to ourselves the stage which the science had reached at 
the beginning of that period. To enable us to do this intelligently, 
however, it will be necessary first to make a very rapid survey of the 
earlier stages of its development. 
Geology, as we understand it at the present day, although 
generally regarded as one of the most recent of the sciences, was 
foreshadowed by the Greek philosopher Pythagoras, so long ago as 
five hundred years before Christ. In the writings of both himself 
and his pupils we find reference to marine shells being buried in 
rocks far from the sea, to the action of streams in carving out valleys, 
the work of the sea in eroding the coast, the phenomena of earth¬ 
quakes and volcanoes, etc. This, truly, was a long step towards a 
correct view of the history of the Earth’s crust; but after the time of 
these early philosophers a dark pall falls on the picture, which hardly 
begins to be drawn aside until two thousand years have elapsed. 
During these long ages, men’s minds were more taken up with the 
rise and fall of empires, the wars between tribes and nations, and the 
controversies of the Church, than they were with abstract questions 
regarding the history of the globe on which they lived. Such at least 
was the condition of matters in Europe, but in Arabia, during the 
tenth century, the philosopher Avicenna was busy investigating the 
properties of minerals. When we come down to the sixteenth 
century, we find in Switzerland, where perhaps the struggle for 
existence was less severe than in other parts of Europe, a patient 
investigator, Gesner, working out the different forms of crystals that 
he found in various minerals, and also drawing figures of fossils. 
The next century finds Palissy in France, Steno in Denmark, Scilla 
in Italy, and Dr. Woodward in England, all groping after the true 
meaning of the fossil remains which they find buried in the rocks. 
The beginning of the eighteenth century finds the same investigations 
carried a little further by Moro and Vallisnero in Italy. The latter 
half of the eighteenth century brings us to the time of Abraham 
Werner, of Silesia, in Austria, who devoted his whole time to the 
enthusiastic study of rocks and minerals. Although he made many 
mistakes, and laid down false theories, which it took a generation to 
eradicate, yet he did invaluable service to science in calling men’s 
attention to subjects which before had attracted but little notice, and 
out of the very strife which he originated the truth was evolved. The 
most valuable result of his work was the elucidation of the true 
