250 SPECULATIVE SCIENCE 



animal or vegetable life, and any of the characteristics used 

 to determine the group that shall claim a given shell or plant. 

 Nay, some chemists are just as eager to abandon the old terms 

 altogether, as Darwin to abolish species. His most advanced 

 disciple will hardly contend that metals and metalloids are the 

 descendants of organic beings, which, in the struggle for life, 

 have gradually lost all their organs : yet is it less strange that 

 inorganic substances should be hard to class, than that organic 

 beings, with their infinitely greater complexity, should be diffi- 

 cult to arrange in neat, well-defined groups ? In the early days 

 of chemistry, a theory might well have been started, perhaps 

 was started, that all metals were alloys of a couple of unknown 

 substances. Each newly discovered metal would have appealed 

 to occupy an intermediate place between old metals. Alloys 

 similarly occupied an intermediate place between the metals 

 composing them ; why might not all metals be simply sets of 

 alloys, of which the elements were not yet discovered ? An alloy 

 can no more be distinguished by its outward appearance than 

 a hybrid can. Alloys differ as much from one another, and 

 from metals, as metals do one from another, and a whole set of 

 Darwinian arguments might be used to prove all metals alloys. 

 It is only of late, by a knowledge of complicated electrical and 

 other properties, that we could feel a certainty that metals were 

 not alloys. 



Other examples may be given, and will hereafter be given, of 

 analogous difficulties of classification ; but let us at once exa- 

 mine what expectations we might naturally form, d priori, as 

 to the probable ease or difficulty in classifying plants and 

 animals, however these may have originated. Are not animals 

 and plants combinations, more or less complex, of a limited 

 number of elementary parts ? The number of possible com- 

 binations of a given number of elements is limited, however 

 numerous these elements may be. The limits to the possible 

 number of combinations become more and more restricted, as 

 we burden these combinations with laws more and more com- 

 plicated insisting, for instance, that the elements shall only be 

 combined in groups of threes or fives, or in triple groups of five 

 each, or in n groups, consisting respectively of a, &, c, d . . . n 

 elements arranged each in a given order. But what conceiv- 



