Human Physiology. ?7 







matters we knew as compounds. In each molecule of an oxide 

 or an acid the chemist sees one of those systems united with 

 one, two, three, or more systems of another kind that are 

 similarly involved. Ascending to orders of compounds succes- 

 sively more heterogeneous, he finds himself obliged to recognise 

 molecular complexities unrepresentable in thought; until, in 

 reaching organic matter, he comes to molecules each of which 

 (taking into account the composite nature of its so-called 

 elements) contains literally more atoms than the visible heaven 

 contains stars atoms combined, system within system, in such 

 ways that each atom, each system, each compound system, 

 each doubly-compound system, has its motion in relation to 

 the rest, and is capable of perturbing the rest and of being 

 perturbed by them; .... and molecules of each kind 

 are specially affected by molecules of the same kind existing 

 in the farthest regions of space. Units of sodium on which 

 sunlight falls beat in unison with their kindred units more than 

 90 millions of miles off, by which the yellow rays of the sun 

 are produced." 



And Mr. Nicholas Odgers has written a work on " The 

 Mystery of Being; or, Are Ultimate Atoms Inhabited Worlds?" 

 a very queer absurdity; for an inhabited world must be 

 composed of an infinitude of ultimate atoms. 



Professor Tyndal tells us that the blue colour of the atmos- 

 phere is caused by myriads of spores or germs of vegetable 

 and animal life, filling the whole air, but quite invisible under 

 the highest power of the microscope. Of course a spore or 

 germ must be composed of innumerable atoms. The sense of 

 smell makes us acquainted with atoms of matter which "no eye 

 can see, no glass can reach." A little violet fills a room with 

 perfume for days; and perfume is particles or atoms of matter 

 floating in the atmosphere; not simple atoms, of course, but 

 violet molecules, each composed of several elements, as car- 

 bon, hydrogen, oxygen, uniting in such forms or combinations 



