DESCRIPTION OF A NITRE CAVE. 24-1 



ccs which have come to my knowledge, relative to the rock 

 ore or sand rocks which yield nitre supposed to possess pecu- 

 liar qualities. 



These sand rocks are generally situated at the head of a ra- 

 vine or narrow valley, lead up a steep hill or mountain : as- 

 cending the streamlets which run through these valleys, the 

 banks close in upon you and become perpendicular. The rocks 

 are frequently from sixty to one hundred feet in height, and 

 jutting over their bases, which rest on a calcareous stratum, often 

 form a shelter large enough to secure a thousand men from the 

 inclemencies of the weather. During the winter season a small 

 rill is precipitated from the top of these rocks, and in summer 

 water generally issues from between the silicious and calcareous 

 strata. These sand rocks which probably once formed a com- 

 plete upper stratum, have been for ages exposed to the destruc- 

 tive operations of rains and frosts, and as they crumble oft' arc 

 carried by torrents into the plains and rivers beneath. The 

 summits of all the hills in the vicinity of Rock castle, Licking 

 and Sandy are still covered by masses of these rocks, which 

 from their beauty and variety of ligure, might at a small dis- 

 tance be mistaken for the ruins of Gothic cathedrals or Baronial 

 castles. Vast blocks of them have rolled down into the valleys, 

 at a period of time so remote, that they are now covered by 

 trees of a luxuriant growth. These rocks when broken per- 

 pendicularly, present a surface consisting of strata so irregular, 

 with regard to their position, and so different in colour and in 

 the size of the particles of sand, that it is impossible to doubt of 

 their Neptunian origin. The minute inspection of them never 

 fails of awakening in the mind the recollection of the shore of 

 some vast lake, where the rage of the winds and the waves has 

 piled up hills of sand, which time consolidates into rock. 



Several years ago the saltpetre-makers discovered that the sand 

 and rubbish sheltered from rains by these rocks contained a rich 

 impregnation of nitre, and that only a small portion of ashes 

 was necessary for its purification. They soon after found that 

 the sand rock itself tasted strongly of saltpetre, and immediately 

 < ommenced the new method of working. 



