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LONDON:
PUBLISHED AT THE OFFICE, BOY COURT, LUDGATE HILL, E.C.

AND SOLD BY ALL BOOKSELLERS.

MDCCCLXXIX.

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DISCUSSION OF THE WORKING HYPOTHESIS We find short line coincidences between many metals THAT THE SO-CALLED

the impurities of which have been eliininated or in which ELEMENTS ARE COMPOUND BODIES.*

the freedom from mutual impurity has been demonstrated

by the absence of the longest lines. By J. NORMAN LOCKYER, F.R.S.

Evidences of Celestial Dissociation. It is known to many Fellows of the Society that I have

It is five years since I first pointed out that there are for the last four years been engaged upon the preparation many facts and many trains of thought suggested by solar of a map of the solar spectrum on a large scale, the work and stellar physics which point to another hypothesisincluding a comparison of the Fraunhofer lines with those namely, that the elements themselves, or at all events some visible in the spectrum of the vapour of each of the metallic of them, are compound bodies. elements in the electric arc.

In a letter written to M. Dumas, December 3, 1873, To give an idea of the thoroughness of the work, at all and printed in the Comptes Rendus, I thus summarised events in intention, I may state that the complete spectrum

a memoir which has since appeared in the Philosophical

Transactions. of the sun, on the scale of the working map, will be half a furlong long; that to map the metallic lines and purity

“Il semble que plus une étoile est chaude plus son the spectra in the manner which has already been de spectre est simple, et que les éléments métalliques se font scribed to the Society, more than 100,000 observations voir dans l'ordre de leurs poids atomiques.*

“ Ainsi nous avons : have been made and about two thousand photographs

"1. Des étoiles très-brillantes où nous ne voyons que taken. In some of these photographis we have vapours com

l'hydrogène, en quantité énorme, et le magnésium ; pared with the sun; in others vapours compared with

« Des étoiles plus froides, comme notre Soleil, où nous each other; and others again have been taken to show which lines are long and which are short in the spectra.

H+Mg+Na I may state, in way of reminder, that the process of

H+Mg+Na+Ca, Fe, ...; purification consisted in this :- When, for instance, an dans ces étoiles, pas de métalloïdes; impurity of mangar.ese was searched for in iron, if the

"Des étoiles plus froides encore, dans lesquelles longest line of Mn was absent, the short lines must also be tous les éléments métalliques sont associés, où leurs lignes absent on the hypothesis that the elements are elementary; ne sont plus visibles, et où nous n'avons que les spectres if the longest line were present, then the impurity was des métalloïdes et des composés. traced down to the shortest line present.

“4. Plus une étoile est âgée, plus l'hydrogène libre The Hypothesis that the Elements are Simple Bodies does disparaît; sur la terre, nous ne trouvons plus d'hydrogène

en liberté. not include all the Phenomena.

“Il me semble que ces faits sont les preuves de The final reduâion of the photographs of all the metallic plusieurs idées émises par vous. J'ai pensé que nous elements in the region 39-40--a reduction I began in the pouvions imaginer une dissociation céleste, qui continue early part of the present year, and which has taken six le travail de nos fourneaux, et que les métalloïdes sont months, summarised all the observations of metallic spectra des composés qui sont dissociés par la température solaire, compared with the Fraunhofer lines accumulated during pendant que les éléments métalliques monatomiques, dont the whole period of observation. Now this reduction has les poids atomiques sont les moindres, son précisément shown me that the hypothesis that identical lines in dif- ceux qui résistent, même à la température des étoiles les ferent spectra are due to impurities is not sufficient. I plus chaudes.” shall show in detail in a subsequent paper the hopeless confusion in which I have been landed. I limit myself on

Before I proceed further, I should state that while

observations of the sun have since shown that calcium the present occasion to giving tables showing how the should be introduced between hydrogen and magnesium hypothesis deals with the spectra of iron and titanium.

for that luminary, Dr. Huggins's photographs have demo n * Paper read at the Royal Society, December 12, 1878.

* This relerred to the old numbers in which Mg=12. Na=23.

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