brooks: applied geology 27 



metals, stones, and earths, dating back to 315 B.C. Pliny's 

 work of four centuries later seems to have been the first attempt 

 at a complete treatise on minerals of economic importance, but he 

 was more concerned in the utilization of the metals than in their 

 mode of occurrence. Other of the ancient writers, notably Aris- 

 totle, touched on geologic subjects, but rather from the standpoint 

 of speculative philosophy than of interest in material problems. 

 Some of the early geographers and historians, like Strabo and 

 Herodotus, discussed the geographical distribution or the exploit- 

 tation of metals. Another field of applied geology is found in 

 treatises on agriculture containing references to character and 

 distribution of soils. Even Virgil in his Bucolics attempts a 

 practical classification of soils. As this dwells on the physical 

 rather than the chemical properties of soil, it would seem to have 

 at least the merit of being in accord with some of the latest scien- 

 tific maxims. 



I have dealt with this subject as if the nations of Europe and 

 western Asia had alone made advances in technology. Mining 

 and metallurgy, even in very early times, were important indus- 

 tries in both India and China, and it is not unlikely that there may 

 be in those countries a literature of practical geology which ante- 

 dates our own. 



The meager records of the early period of mining give no clew 

 to the knowledge of applied geology held by the ancients. But 

 that they were not entirely ignorant of its principles is to be pre- 

 sumed from the importance of the mining industry, and the ab- 

 sence of written records does not argue against this theory. The 

 same is true of other arts. We do not assume, for example, that 

 the principles of mechanics applied to structures were not under- 

 stood because there were no written treatises on architecture until 

 centuries after many periods of architecture had successively 

 developed and declined. 



Scant as is the literature of mineralogy and mining up to the 

 early part of the Christian era, the succeeding ten or twelve cen- 

 turies are almost entirely without records. This was the medieval 

 period of intellectual stagnation — the eclipse of scientific and 

 critical thought. The Arabs, who alone preserved the traditions 



