110 BIOGRAPHIES OF SCIENTIFIC MEN 



issue, his baronetcy, like that bestowed on his confrere 

 Murchison, became extinct. 



In 1858, one year before the publication of Darwin's 

 famous book, The Origin of Species, he revisited Sicily in 

 order to make observations upon the structure of Etna, 

 and, as already stated, he refuted the theory of " Eleva- 

 tion Craters " the " cupolas " of the German geologists. 

 This theory stated that all great volcanoes were formed 

 of masses originally deposited in a horizontal position, 

 and subsequently blown up into a conical form. Lyell 

 proved that in the case of Etna, during the earlier periods 

 of its history, the piling up of materials went on 

 around a centre which is now situated at a distance of 

 nearly four miles from the present focus of eruption. His 

 " Memoir on the Lavas and Mode of Origin of Mount 

 Etna" is to be found in the Philosophical Transactions 

 for 1858. 



In 1863 Sir Charles Lyell published his famous work 

 on The Geological Evidences of the Antiquity of Man, with 

 Remarks on Theories of the Origin of Species by Variation. 

 In this marvellous book a vast amount of details and 

 research are brought forward in regard to prehistoric man, 

 and the times in which he lived. Concerning the Pleis- 

 tocene alluvial deposits in many European valleys, there 

 were found " works of art of the ages of iron and bronze, 

 and of the later or Neolithic stone period. In the more 

 ancient or Palaeolithic gravels there have been found in 



