The idea of a progressive evolution in plants had been suspected by many botanists, but the genius of Darwin developed it. Living plants were pictured as a multitude of units competing for food, light, air, and room for growth, and struggling against unfavorable environments. The classification of tissues was begun, and the phenomena of absorption of water and salts, the ascent of sap, the absorption of minerals and nitrogen, and metabolism and growth were elucidated. Investigations were made into the nature and functions of chlorophyll and other plant substances. These studies resulted in suggesting means for improving crops by artificial selection, as shown in the work of Luther Burbank.
CHAPTER XIV
GEOLOGY, METALLURGY, AND METEOROLOGY
Geology is essentially a nineteenth century product. Fossils, minerals, rocks, and rock strata had attracted more or less attention from the earliest times. The Egyptians, Greeks, and Romans had books dealing with such subjects, and Greek philosophers, like Aristotle, lectured upon them. But it was only in the last century that geology was placed upon a scientific basis and began to make progress. The reformation was begun by Cuvier's work on paleontology, the chemical and physical discoveries of the eighteenth century, and the works of Hooke, Boyle, Buffon, Linnæus, and others. The special technique required in geographical research could not be developed until the biological, anatomical, botanical, and physical sciences had been established on a scientific plane. That is why geology remained for so many centuries undeveloped, and then rapidly advanced during the nineteenth century. Its preparation was long and involved, while its fruition was rapid and brilliant.
William Smith (1769-1839), called the father of English geology, was a mining surveyor engaged in making colliery and farm surveys in Oxfordshire and the west of England. His professional work led him to study the coal outcrops, and in 1793 he mapped the inclined coal deposits in Somersetshire. The numerous rock strata accompanying the coal beds contained fossils which he found could be used to identify the beds in that field with others in northern counties. He published an account of this manner of using type fossils for identifying fossiliferous rock formations in 1799, and in 1815 issued his geological map of England, Wales, and southern Scotland. This map showed the advantages that scientific geology and mineralogy offered to industry and caused scientists all over Europe to study geological phenomena and make sketch maps of local geology.
A work on paleontology, dealing with the fossils of the Old Red Sandstone deposits, published in England by Hugh Miller (1802-1856), which had an enormous popularity and has been described as the most fascinating book ever written on a geological subject, followed Smith's "Strata Identified by Organized Fossils." A large amount of mapping resulted from the issuing of these two works. These maps called for detailed descriptions, and these in turn resulted in the accumulation of many interesting data which, when collected, and systematized, led to many important discoveries.
While these authors were preparing their books, Werner, De Luc, De Saussure, Lamarck, and others were working out paleontological problems, Romé de l'Isle, Brongniart, Haüy, d'Aubuisson, and others were building up the science of mineralogy.
"The Theory of the Earth," of Dr. James Hutton (1726-1797), was published in 1785, and in an enlarged form in 1795. This book described the metamorphoses of sand into sandstones, quartzites, schists, and other rock formations; the work of floods and lava floods; the sculpturing powers of streams, rains, and winds, etc. He indicated the effects of the alternate sinking and raising of strata through earth shrinkings and volcanic phenomena, and taught that purely physical causes can be found for every geological effect.
Playfair's "Illustrations of the Huttonian Theory of the Earth" augmented the teachings of Hutton's book, while works by Jameson, Kirwan, Boué, Sir James Hall, Daubrée, St. Claire-Deville, Buckland, Sedgwick, Bakewell, Breislak, Maclure, and others rapidly appeared sustaining the Huttonian, or the Wernerean theories of geological deposition.