130 Dr Hunt, Celestial Chemistry [Nov. 28, 



the scientific progress of the last generation, renders still more 

 evident the wonderful prevision of him who already, two centuries 

 since, had anticipated most of the recent speculations and con- 

 clusions regarding cosmic chemistry. 



As an introduction to the inquiries before us, and in order to 

 show the real significance of the speculations of Newton, it will 

 be necessary to review, somewhat at length, the history of certain 

 views enunciated almost simultaneously by the late Sir Benjamin 

 Brodie, of Oxford, and the present writer, and subsequently de- 

 veloped and extended by the latter. In part I. of his Calculus of 

 Chemical Operations, read before the Royal Society, May 3, 1866,. 

 and published in the Philosophical Transactions for that year, 

 Brodie was led to assume the existence of certain ideal elements. 

 These, he said " though now revealed to us through the numerical 

 properties of chemical equations only as implicit and dependent 

 existences, we cannot but surmise may sometimes become, or may 

 in the past have been, isolated and independent existences." Shortly 

 after this publication, in the spring of 1867, I spent several days in 

 Paris with the late Henri Sainte-Claire Deville, repeating with 

 him some of his remarkable experiments in chemical dissociation, 

 the theory of which we then discussed in its relations to Faye's 

 solar hypothesis. From Paris, in the month of May, I went, as the 

 guest of Brodie, for a few days to Oxford, where I read for the first 

 time and discussed with him his essay on the Calculus of Chemical 

 Operations, in which connection occurred the very natural sug- 

 gestion that his ideal elements might perhaps be liberated in solar 

 fires, and thus be made evident to the spectroscope. I was then 

 about to give, by invitation, a lecture before the Royal Institution 

 on The Chemistry of the Primeval Earth, which was delivered 

 May 31, 18G7. A stenographic report of the lecture, revised by 

 the author, was published in the Chemical News of June 21, 1867, 

 and in the Proceedings of the Royal Institution. Therein I con- 

 sidered the chemistry of nebulae, sun and stars in the combined 

 light of spectroscopic analysis and Deville's researches on dis- 

 sociation, and concluded with the generalization that the " breaking 

 up of compounds or dissociation of elements by intense heat is a 

 principle of universal application, so that we may suppose that all 

 the elements which make up the sun or our planet would, when so 

 intensely heated as to be in the gaseous condition which all matter 

 is capable of assuming, remain uncombined ; — that is to say would 

 exist together in the state of chemical elements, whose farther 

 dissociation in stellar or nebulous masses may even give us evi- 

 dence of matter still more elemental than that revealed in the 

 experiments of the laboratory, where we can only conjecture the 

 compound nature of many of the so-called elementary substances." 



The importance of this conception, in view of subsequent dis- 



