250 MODERN SCIENCE READER 



out with abstractions ; there is scarcely a point at which it 

 touches reality; yet it finds a sort of verification in the 

 delicate experimental results secured at the Royal Institu- 

 tion and the Cavendish Laboratory. An "Urstoff" is im- 

 plied, nay, insisted upon by an array of well-ascertained 

 facts. Sir William Crookes identified it, a quarter of a cen- 

 tury ago, with the "radiant matter" in his vacuum-tubes. 

 It escapes irresistibly from certain substances; imprisoned 

 and bound in the fetters of some mysterious attraction, 

 it constitutes all. In the free state it is matter if the 

 name should be applied to it at all reduced to the ranks, 

 generalized, stripped of its distinctions, the same from 

 whatever source derived; it is matter in potency, rather 

 than in act, intangible, inaccessible to sense-perception, 

 probably indifferent to the solicitations of gravity. Critic- 

 ally considered, it is found to consist of countless swarms 

 of "electrons," traveling with prodigious speed; and out 

 of electrons, diversely aggregated, the chemical units or 

 atoms of ordinary matter are apparently built up. Elec- 

 trons may then fairly be regarded as the modern equiva- 

 lent of the formless "protyle" of Greek thinkers. 



The dogmas of the fundamental unity of matter, and of 

 the "accidental" character of its sorts and species, evi- 

 dently provided a rational justification for the toils of al- 

 chemists. But much more was needed to give their art the 

 vigorous vitality, which enabled it, during twelve hundred 

 years, to withstand the blasts and counterblasts of opinion. 

 It lived and throve, not because of the truths which it 

 misrepresented, but in virtue of the greed of gain which 

 it encouraged, and the frauds, half visionary, half vulgar, 

 by which its practice was sheltered and surrounded. Al- 

 chemy was from the first intertwined with the varied 

 forms of occult belief which crept westward, through 

 Alexandria, from the valley of the Euphrates in the early 

 centuries of our era. Egypt in those days swarmed with 

 Gnostics, and Gnosticism was in close alliance with every 

 form of Oriental superstition. Pseudo-sciences, accordingly, 



