14 St. J ago. 



PART I. 



is about 600 feet ; it is composed of bright red, highly 

 scoriaceous rock of a basaltic nature ; on one side of its 

 summit there is a hollow, probably the last remnant of 

 a crater. Several of the other hills of this class, judging 

 from their external forms, are surmounted by much 

 more perfect craters. When sailing along the coast, it 

 was evident that a considerable body of lava had flowed 

 from Red Hill, over a line of cliff about 120 feet in 

 height, into the sea : this line of cliff is continuous 

 with that forming the coast, and bounding the plain on 

 both sides of this hill ; these streams, therefore, were 

 erupted, after the formation of the coast-cliffs, from 

 Red Hill, when it must have stood, as it now does, 

 above the level of the sea. This conclusion accords 

 with the highly scoriaceous condition of all the rock on 

 it, appearing to be of subaerial formation ; and this is 

 important, as there are some beds of calcareous matter 

 near its summit, which might, at a hasty glance, have 

 been mistaken for a submarine deposit. These beds 

 consist of white, earthy, carbonate of lime, extremely 

 friable so as to be crushed with the least pressure ; the 

 most compact specimens not resisting the strength of 

 the fingers. Some of the masses are as white as quick- 

 lime, and appear absolutely pure ; but on examining 

 them with a lens, minute particles of scoriaB can always 

 be seen, and I could find none which, when dissolved in 

 acids, did not leave a residue of this nature. It is, 

 moreover, difficult to find a particle of the lime which 

 does not change colour under the blowpipe, most of 

 them even becoming glazed. The scoriaceous frag- 

 ments and the calcareous matter are associated in the 

 most irregular manner, sometimes in obscure beds, but 

 more generally as a confused breccia, the lime in some 

 parts and the scorias in others being most abundant. 

 Sir H. De la Beche has been so kind as to have some of 



