796 THE POPULAR SCIENCE MONTHLY. 



by means of hieroglypMcs to communicate thought ? Do we 

 know the history of the first attempts at making type? Do we 

 know all the processes in the manufacture of the type before us ? 

 That type is a metal, taken from the mines, perhaps formed in the 

 Devonian or even the Archsean period of geological time. Earth's 

 metals have definite relations to the sun's spectra, to the spectra 

 of the fixed stars, to the spectra of the chaotic nebulse floating like 

 evening clouds through the starlit depths of space. If we do not 

 know these, we must confess that we understand but little of the 

 relations involved in the production of a book. 



We pick up a piece of metal that we call gold. A chemist 

 tells us that we are rash in calling this gold, for he suspects that, 

 if its molecular relations were understood, it would be clearly 

 seen to be nothing but hydrogen. He says that the last analysis 

 would probably show sulphur, iron, lead, oxygen, silver, copper 

 in fact, all the metals and all the so-called elements to be one and 

 the same substance with a different molecular arrangement. The 

 physicist says he shall no longer place hard and fast lines of de- 

 marcation between heat, light, and electricity. The psychologist 

 has ceased to view perception, memory, thought, emotion, and 

 will as different forces. The metaphysician declares that we 

 might as well stop writing treatises on special subjects, for all the 

 sciences are merely various phases of one great underlying science, 

 though our ignorance has not yet allowed us to see the intimate 

 relations between all, just as the chemist's ignorance has not 

 permitted him to see that gold, silver, and lead are the same 

 substance. 



We proceed practically in this way to untie this unpleasant 

 Gordian knot of ignorance. In the case of the book we say : 

 " We shall deliberately disregard those relations which do not 

 vitally concern our immediate selfish interests. Our present aim 

 is to read that novel, and we do not now care how long mankind 

 groped in ignorance, when books were first printed, how the type- 

 metal is prepared, whence it came, or what relations the spectro- 

 scope shows it to have in common with the sun, the stars, and the 

 nebulae." 



Considerations like these show us how incomplete is human 

 truth, how one-sided and partial, how trivial and superficial it 

 would seem to a being of complete intelligence. So long as the 

 struggle for existence co7itinues, so long must human truth develop 

 especially on its selfish side. Electricity will be investigated 

 along the line of its utility to the self. Engineering skill will 

 construct bridges with vast spans over which trains may roll 

 laden with flour and corn and beef. In justice to the aspirations 

 of the human soul, it may be said that many a one has been forced 

 to expend its energies in routine struggles for bread when that 



