196 ON THE ORIGIN OF THE PLANETARY SYSTEM. 



ADDENDUM. 



THE sentences on page 193 gave rise to a controversial 

 attack by Mr. J. C. F. Zoellner, in his book * On the 

 Nature of the Comets,' on Sir W. Thomson, on which I 

 took occasion to express myself briefly in the preface to the 

 second part of the German translation of the ' Handbook of 

 Theoretical Physics/ by Thomson and Tait. I give here the 

 passage in question : 



' I will mention here a farther objection. It refers to the 

 question as to the possibility that organic germs may occur 

 in meteoric stones, and be conveyed to the celestial bodies 

 which have been cooled. In his opening Address at the 

 Meeting of the British Association in Edinburgh, in August 

 1871, Sir W. Thomson had described this as " not unscien- 

 tific." Here also, if there is an error, I must confess that I 

 also am a culprit. I had mentioned the same view as a 

 possible mode of explaining the transmission of organisms 

 through space, even a little before Sir "W. Thomson, in a 

 lecture delivered in the spring of the same year at Heidel- 

 berg and Cologne, but not published. I cannot object if any- 

 one considers this hypothesis to be in a high, or even in the 

 highest, degree improbable. But to me it seems a perfectly 

 correct scientific procedure, that when all our attempts fail 

 in producing organisms from inanimate matter, we may 

 inquire whether life has ever originated at all or not, and 

 whether its germs have not been transported from one 

 world to another, and have developed themselves wherever 

 they found a favourable soil. 



1 Mr. Zoellner's so-called physical objections are but of 

 very small weight. He recalls the history of meteoric stone, 

 and adds (p. xxvi.): " If, therefore, that meteoric stones covered 

 with organisms had escaped with a whole skin in the smash- 



