34 THE POPULAR SCIENCE MONTHLY. 



materiality of air, and the still more recent times when it was found 

 that gases other than air had existence. 



Some further speculations, enkindled by the green ray observed in 

 the sunshine, may be here presented as relevant to the subject. Du- 

 mas, the eminent French chemist, sought by very careful determina- 

 tion to prove that all atomic weights were exact multiples of that of 

 hydrogen. He found them to be multiples of a number one-fourth that 

 of hydrogen, whence the tenuous masses which lie above the hydrogen 

 on the sun's surface are supposed to be one-fourth the specific gravity 

 of the lightest gas we commonly know. And, as the spectrum it 

 yields is the simplest known or even possible, it is thought that this 

 new unit of the atomic scale may be primal matter, and the source of 

 all material forms. This conjecture is not unsupported by other con- 

 siderations, for, in the four kinds of stars regarded in the order of their 

 brightness and heat, there is a progressively increasing variety of 

 gases as they approach a lower temperature a suggestion this as to 

 the origin of our sixty-three so-called elements in chemistry. 



In domains above the plane of physics, we can observe many 

 beautiful cases of the law of continuity. On a window-pane in winter 

 we can notice structural forces beginning their work where there has 

 been, as far as we could see, no structure. We may breathe on the 

 glass, and no microscope can there reveal any definite direction in the 

 disposal of the moisture. Yet, from it a symmetrical architecture of 

 frost slowly arises. We may take a crystal just deposited from a 

 solution, break off a corner from it, and replace it in the liquid whence 

 it came, when the damage will be accurately repaired. 



Between the inorganic and the organic kingdoms of Nature the 

 old partition-walls have at many points been removed. Formic acid, 

 such as ants secrete, has been made artificially by the synthesis of its 

 elements ; and so have other products, formerly regarded as purely 

 organic. Prof. Huxley maintains the opinion that, in the past, highly- 

 complex chemical compounds have passed into the state of what he 

 calls protoplasm, the simplest basis of organic life. The controversy 

 about spontaneous generation is not whether the organic is contained 

 and potential in the inorganic, but whether the transition can be arti- 

 ficially effected now. 



Plants, like the fly-catcher, which closes on venturesome insects 

 and absorbs their juices, show us how powers, commonly supposed to 

 be exclusively animal, may be shared by members of the vegetable 

 world. The sensitive-plant has something very like the nervous sys- 

 tem which marks the highest types of life, for it not only shrinks 

 when rudely touched, but also when exposed to fumes of chloroform. 

 In the same direction points what in plants generally seems to paral- 

 lel instinct in animals. If a layer of soil near the surface of the 

 ground be unusually rich and moist, the rootlets in growth are spread 

 almost wholly along that layer, while in any other case they descend. 



