170 
crystallization radiating from a point, or centre, approach- 
ing in appearance the inside of tab. 38. Thus the sub- 
stance consolidated chiefly as to its inside; but being in 
some parts of a more earthy fracture, there probably was 
much undissolved matter, which interrupted the crystalli- 
zation, and so it is occasionally irregular in its appearance. 
Some parts of the outside, therefore, it seems, were suc- 
cessively covered with these rings, as the water evaporating, 
in the time of aggregation, allowed of them: afterwards 
the substance of the coat adhered less perfectly between wet 
and dry, not so easily attaching to the drier edges of the 
rings or circles: and this may be in part understood; for it 
is only where the coat easily separates that these circles are 
seen, and should we by a little help detach any other ad- 
jacent part of the coat, there is little or no continuation of 
them. Sometimes there are partially two or three coats, 
some very thin, and occasionally two or three balls are 
found adhering together with the circles on them. These 
stones are not always what are called Swine- or Stink-stones, 
some having little or no Sulphuretted Hydrogen, which 1 
believe is the cause of fetidness in this particular species, 
though not in all Stink-stones. 
