22 8 THE POPULAR SCIENCE MONTHLY. 



the determination to submit my views, not without some misgiving, to 

 the touchstone of scientific criticism. 



For the purposes of my theory, stellar space is supposed to be filled 

 with highly rarefied gaseous bodies, including hydrogen, oxygen, nitro- 

 gen, carbon, and their compounds, besides solid materials in the form 

 of dust. Each planetary body would in that case attract to itself an 

 atmosphere depending for density upon its relative attractive impor- 

 tance, and it would not seem unreasonable to suppose that the heavier 

 and less diffusible gases would form the staple of these local atmos- 

 pheres ; that, in fact, they would consist mostly of nitrogen, oxygen, 

 and carbonic acid, while hydrogen and its compounds would pre- 

 dominate in space. 



In support of this view it may be urged that, in following out the 

 molecular theory of gases as laid down by Clausius, Clerk Maxwell, 

 and Thomson, it would be difficult to assign a limit to a gaseous at- 

 mosphere in space ; and, further, that some writers among whom I 

 will here mention only Grove, Humboldt, Zollner, and Mattieu "Wil- 

 liams have boldly asserted the existence of a sj>ace filled with matter. 

 But Newton himself, as Dr. Sterry Hunt tells us in -an interesting 

 paper which has only just reached me, has expressed views in favor of 

 such an assumption. 



The history of Newton's paper is remarkable and very suggestive. 

 It was read before the Royal Society on the 9th and 16th of Decem- 

 ber, 1675, and remained unpublished until 1757, when it was printed 

 by Birch, the then secretary, in the third volume of his " History of 

 the Royal Society," but received no attention ; in 1846 it was pub- 

 lished in the "Philosophical Magazine " at the suggestion of Harcourt, 

 but was again disregarded ; and now, once more, only a few months 

 since, a philosopher on the other side of the Atlantic brings back to 

 the birthplace of Newton his forgotten and almost desjrised work of 

 two hundred years ago. 



Quoting from Dr. Sterry Hunt's paper : 



Newton in his Hypothesis imagines "an ethereal medium much of the same 

 constitution with air, but far rarer, subtler, aud more elastic. . . . But it is not 

 to be supposed that this medium is one uniform matter, but composed partly of 

 the main phlegmatic body of ether, partly of other various ethereal spirits, much 

 after the manner that air is compounded of the phlegmatic body of air inter- 

 mixed with various vapors and exhalations." Newton further suggests in his 

 Hypothesis that this complex spirit or ether, which, by its elasticity, is extended 

 throughout all space, is in continual movement and interchange. '* For Nature 

 is a perpetual circulatory worker, generating fluids out of solids, and solids out 

 fluids ; fixed things out of volatile, and volatile out of fixed ; subtile out of 

 gross, and gross out of subtile ; some things to ascend and make the upper ter- 

 restrial juices, rivers, and the atmosphere, and by consequence others to descend 

 for a requital to the former. And as the earth, so perhaps may the sun imbibe 

 this spirit copiously, to conserve his shining, and keep the planets from receding 

 further from him ; and they that will may also suppose that this spirit affords or 



