494 Mr. He ns low’s Supplementary Observations to 
hue, very compact, and often an abundant ingredient. The agates 
are sometimes of a large size and very beautiful texture, but in 
general so full of flaws as to render them useless to the lapidary. 
Though they may be picked out from the sandstone, their union 
with this appears once to have been more intimate than at present, 
from a circumstance which happens with respect to the thin veins 
of crystallized carbonate of lime which traverse the bed in every 
direction : these invariably pass through every substance which 
they meet with in their course, even the smallest agates; from 
whence it would seem that the narrow fissures, into which this 
infiltration has taken place, were caused by the shrinking of the 
mass, during its consolidation, at a period when the texture of the 
different ingredients was more homogeneous than at present. If a 
crack of this nature were to take place now, it would most assuredly 
be turned from its regular course upon meeting with those agates, 
pass round them, detaching one side from the matrix, rather than 
traverse them in the manner described. 
This bed is here seen penetrating and mixing with the clay-slate. 
Dr. Berger has committed a great mistake in supposing the whole 
isthmus of Langness to be composed of red sandstone. This is 
confined to the beach, and a small space inland, down the western 
side ; the remainder of the isthmus being composed of clay-slate. 
The appearance also is totally different from that at Peel, and is 
that of an exceedingly rude conglomerate of quartz, slate, &c. in 
masses one or two feet in diameter, mixed with smaller fragments, 
and held together in a loose manner by a ferruginous cement. 
Wherever the removal of a portion of this bed, by the influence of 
the tide, had afforded an opportunity of examining the slate beneath, 
this appeared to have been rent and split in every direction into 
fragments, and these again cemented together, so that those belonging 
