NATURAL HISTORY OF THE EIGHTEENTH CENT. 415 



The contending geologists, or the Vulcanists and Neptunists, as the 

 respective sects were called, soon came to occupy themselves more 

 with framing ingenious arguments for attack and defence of their 

 theories than with discovering and comparing actual facts. A new 

 school emerged from this dispute, whose disciples resolved to devote 

 themselves to assiduous observation and a far more extensive accumu- 

 lation of facts, instead of framing theories. The mere accumulation 

 of facts unrelated by general principles could not, however, as we have 

 already had occasion to remark, ever constitute a science. By a re- 

 action from the former immature speculations, geologists in the earlier 

 part of the present century certainly did desist from framing systems, 

 and devoted themselves to the patient multiplication of observations. 

 This conduct had the great advantage of furnishing more solid data, 

 and of disarming the hostility which the bold speculations of Hutton 

 and others had raised against the infant science. The establishment 

 of palaeontology as a distinct science, and the foundation of the Geo- 

 logical Society of London, both of which date from the beginning of 

 the present century, may be considered as the commencement of a 

 new epoch in geological science, and will engage our attention in a 

 subsequent chapter. 



The student of the mineral kingdom is conversant with objects 

 which possess an interest and beauty of which the uninitiated and the 

 inattentive are little aware. Let any person, who has been accus- 

 tomed to hurry through a museum with merely a passing glance at the 

 cases of mineral specimens, examine these specimens in detail, and he 

 will not fail to be struck with the variety and beauty of the colours, 

 forms, and conditions of surface which minerals can display. The 

 apparently inexhaustible diversity of the specimens, and the gorgeous 

 or elegant beauty of many of them so different from anything that 

 might be anticipated from ordinary observation of the mass of mate- 

 rials constituting our planet will astonish the intelligent beholder. 

 He will see the most splendid tints of birds and flowers rivalled or 

 excelled ; he will see iridescent plays of colours in every key, from fiery 

 coruscation to the delicate dreaminess of the opal; he will see the 

 whole gamut of colours, hues, and tints, in conditions ranging from the 

 most perfect lucidity to the deepest opacity : the ruby and the eme- 

 rald, the sapphire and the topaz, will be included in the objects of his 

 contemplation ; strange phenomena of refracted light and electrical 

 polarity will display themselves ; every quality of texture, from fibres 

 soft and delicate as silk to the hardness and compactness of adamant, 

 will come under observation. Strangest of all, in minerals may be 

 seen Nature's geometry of straight lines and. planes, which are found 

 in no other of her productions than in crystals. 



Mineralogy, as a science of classification, relies upon discrimination 

 of chemical constitution, crystalline forms, physical properties, such 

 as hardness, specific gravity, colour, lustre, optical properties, etc. The 



