360 



SCIENTIFIC THOUGHT. 



cold, heavy, lifeless, and lightless body behind. 1 The 

 action of attractive power would sometimes reveal the 

 existence of cold bodies, with specific gravity much in 

 excess of our earth, as in the case of the satellite of 

 Sirius, and the spectroscope would reveal clusters of 

 stars or nebulae in the various stages of development, 

 such as the nebular hypothesis suggested as making up 

 the genetic process of our planetary system. Much 

 uncertainty and much conjecture must of course exist 

 in these chapters of science, which those who are in 

 full possession of the accumulated and yet very im- 

 perfect facts may venture to elaborate in a more or 

 less plausible or fanciful manner. Such attempts to 

 si. write the history of the universe have been made in 

 the cosmos an original fashion by M. Faye in France 2 and Sir 



-Faye and J 



Lockyer. ISTorman Lockyer in this country. They have tried 



1 See Helmholtz, ' Vortrage und 

 Reden,' vol. ii., 3rd ed., p. 88, &c. 



2 ' Sur 1'Origine du Monde.' 2nd 

 ed., Paris, 1885. The author, 

 finding the celebrated cosmogonic 

 hypothesis of Laplace in "full 

 contradiction " with the actual 

 state of science, takes up an original 

 theory of Descartes, that of vortices, 

 in order to characterise not the 

 actual, but the initial, stage of the 

 solar system (see Preface) : " Autre- 

 fois, je veux dire il y a une vingt- 

 aine d'annees, on avait les coudees 

 franches pour imaginer un systeme 

 cosmogonique : il suffisait de 1'ac- 

 comruoder aux notions contem- 

 poraines d'Astronomie solaire et 

 de me'canique celeste. II n'en est 

 plus de meme aujourd'hui, car la 

 thermodynamique assigne a notre 

 Soleil une provision limite"e de 

 chaleur, 1'Analyse spectrale nous 

 revile la constitution intime des 

 astres les plus e"loigne"s, et la pale- 



ontologie nous fait remonter a des 

 epoques ou il n'y avait, sur notre 

 globe, ni saisons, ni climats. " 



3 Whereas M. Faye has ingen- 

 iously modified the original and 

 older nebular hypothesis so as to 

 account for the anomalies in the 

 movement of some of the members 

 of our planetary system, which 

 were unknown or unexplained in 

 Laplace's time, and has trier! to 

 account for the phenomena of loss 

 and supply of heat which thermody- 

 namical theory and palaeontological 

 records reveal, Sir Norman Lockyer 

 has during more than thirty years 

 been occupied with the elaboration 

 of a special theory which tries to 

 harmonise the revelations of the 

 spectroscope as to the chemical 

 constitution of the sun and other 

 stars with the more recent develop- 

 ments of the atomic theory as 

 suggested by chemical and electrical 

 phenomena observed in our labora- 



