35i Mr. Horner on the Geology of the 



1. A crystalline limestone which burns to a white lime mixed 

 with brown spots, falling very readily to powder. 100 grains 

 dissolved in dilute acid left 7 grains of residuum, which con- 

 sisted of about 4 grains of oxide of iron, the remainder being 

 silica. 



2. The preceding variety mixed with a considerable quantity of 

 quartz, and of yellow calcareous spar. This latter substance 

 occurs also in veins and probably pervades all the calcareous 

 strata. A piece of that stone when thrown into dilute acid 

 leaves a fragment which does not fall into powder. 



3. This variety is intermixed with a smooth slaty substance with 

 an unctuous feel, which is probably talcose slate : it leaves a 

 considerable quantity of large grains of quartz when thrown 

 into dilute acid. 



None of these calcareous strata are used for any other purpose 

 than to mend the roads, and they do not seem to be known as 

 limestones, most probably because there is a much better limestone* 

 so near at hand. The first variety would yield a very good lime, 

 if reliance for that purpose can be placed on my minute expe- 

 riments ; a trial on the large scale might very easily be made in one 

 of the neighbouring lime kilns. The principal calcareous stratum 

 is five feet thick. 



Immediately behind the village of Bagborough I found a calcareous 

 stratum occurring in the same way as those at Halsey cross. 



§ 19. My observations were principally confined within the 

 limits I have already mentioned, but having had an opportunity of 

 making a cursory examination of the country between Porlock and 

 Ilfracombe, and as the rocks occurring in that part of the country 

 are connected with those I have been describing, I shall briefly state 

 the few notes I made. My route was from Porlock, by Culbone, 



