[ *7 ] 
Lump. There are fome on which one may obferve 
fhining Stria, that feem to be of a metallic Sub- 
ftance. 
I have heard, that a great many Stones like thefe 
are alfo found on the Sides of a Brook in Spain $ 
from whence, without Doubt, they got the Name 
they are commonly called by, of Ferreles d Efpagne. 
About Two Months ago, happening to take a 
Walk in the Road newly made between Bagneres 
and the Fontaine de Salut , I perceived, that, in dig- 
ging the Ditch on the Side of the Road, the Work- 
men had laid open a Rock of a Sort of imperfect 
Slate, but fofter, and of a lighter Colour, than Slate 
commonly is. The Rock itfelf is compofed of Layers 
or Beds lying almoft parallel one over the other : 
The Subftance of the Slate feems to be a Compofttion 
of Fibres or Strings, placed on the Sides of each other, 
and equally inclined to their Beds or Layers ; whence 
it comes, that, upon breaking them with a Hammer, 
the Pieces, fometimes, are pretty like the Figure of a 
regular Parallelopipede with oblique Angles. 
Upon a narrower Examination of this Sort of Slate, 
I found a great Number of Parallelopipede Stones, 
like thofe before fpoken of, only fmaller : I have 
feen them of all Sizes, from thofe in which the larged 
Side is but of Two or Three Lines. I obferved alfo, 
after having broken to pieces feveral little Bits of 
Slate, certain black Spots; which, by the Help of a 
Microfcope, I found to be real figured Stones. 
Beftdes this, I took notice, that everyone of thefe 
Stones, as long as it remains in the Rock, is always 
found between Two Bundles or Clufters of tranfpa- 
rent Fibres, of which, generally, one is placed on 
D 2 the 
