THE CHEMICAL ELEMENTS. 749 



man occupies an intermediate position in creation, with a micro- 

 cosmos beneath, as far removed from the order of his perceptions 

 as is the macrocosmos above him. To one who realizes what must 

 be the complex dynamical relations as well as the order of magni- 

 tude of these molecular systems, the diagrams of molecular struct- 

 ure which may be seen in any work on organic chemistry can not 

 but appear as crude and childish as the figures of constellations 

 on a celestial globe ; and when, as frequently happens, the student 

 confounds the sign and the substance, one can hardly refrain from 

 a little good-natured laugh at the spider-leg formulse, as a noted 

 German chemist is in the habit of calling them. Still, these are 

 only the conventional forms of a good working theory, which is 

 a noble product of human thought and an effective means of 

 advancing knowledge. 



For one who has followed the history of chemical thought 

 from the first, it is easy to discover great imperfections in our 

 present system. The assumption that, with more than seventy 

 different kinds of atoms already known, uniting in such varied 

 combinations to form molecules, only like molecules should ever 

 aggregate to form material masses, is a solecism in the very post- 

 ulates of the system ; and the whole question of molecular combi- 

 nation is one which is still in abeyance. Analogy forbids us to be- 

 lieve that, down to a certain limit of dimensions that we call mole- 

 cules, the constitution of matter is of a wholly different sort from 

 that which appears on subdividing the molecules. It is an equally 

 incredible assumption that all atoms of the same element are so 

 many independent creations exactly alike in every respect. Then, 

 as our knowledge increases, the distinctions between the chemical 

 elements are becoming less marked and their relations to each 

 other more intimate. They are beginning to appear, not as iso- 

 lated units, but as links in a complex network, which presents an 

 unbroken continuity throughout. The recent study of the rarer 

 earths leaves us in doubt whether we have an indefinite number of 

 elements, or only one under unnumbered manifestations ; and the 

 later results of spectrum analysis seem to indicate quite clearly 

 that, at the high temperatures of the sun and of the fixed stars, 

 many of our terrestrial elements are decomposed. From a mathe- 

 matical analysis of the spectra, Griinwald maintains — and supports 

 his conclusion by a great array of confirmatory measurements 

 — that the remarkable solar spectrum line called helium, and the 

 equally well-marked line of the sun's corona, come from two 

 constituents of hydrogen gas, the first of which is somewhat 

 heavier and the last far lighter than hydrogen gas ; and this con- 

 clusion, if not finally accepted, is regarded as highly probable 

 by men of such scientific sobriety as Liveing and Dewar, of 

 Cambridge, in England — men who are acknowledged as among 



