IllON IN THE LIME. 53 
down near Deadman’s Bay, and in one instance in 
the vicinity of Torquay, besides which limestone 
has magnesian qualities in a less degree in many 
other places.* Although, it is most usually con¬ 
founded with the substance of the lime which it 
joins, yet, it likewise is found connected at an abso¬ 
lute line of junction perfectly distinct ; is rarely 
slaty. The South Devon limestone is greatly per¬ 
vaded by seams of calcareous spar in numerous 
situations, and this substance (used much for garden 
paths) is likewise found much in the narrow fissures 
of the rock, adhering firmly to the surfaces where 
the beds are approximating. It is also rarely dis¬ 
covered in masses of several tons weight towards 
the surface. Caverns and fissures^ are common in 
this rock, and are most generally lined on their roofs 
and floors respectively by stalactitic and stalagmitic 
concretions. Jasper is found sparingly in small 
patches and veins in the limestone. Calaminaris 
is also a reputed production of the Yealmpton rock. 
Although, from defective, knowledge of mineral¬ 
ogy, I am not able to say any thing generally on 
the subject, I must yet beg to introduce a trivial 
notice of an irregular vein of iron , lately discovered 
in the lime of Yealm Bridge. It consists of discon¬ 
nected blocks of ore lying loose in clay, or joined 
to the bed of lime ; the fissure wherein they are 
found, is lined with soft slaty matter, and pursues 
a course nearly due east and west, but as yet has 
not been much examined ; the largest block taken 
out weighs about 30 lbs. Several proofs of the con¬ 
temporaneousness of this metallic deposit with the 
lime bed, here presented themselves ; 1st. a block 
* See “ Guide to the Watering Places.” Part II. 
f With regard to the origin of these caves,—may they possibly 
have been due to the escape of gaseous matter at the period of 
deposition of the rock ? 
