454 
countable; judging from a specimen in my possession, which I 
understand was obtained by the late Mr. Strange, from Germany, at 
considerable trouble and expense. Its form is that of a long square, 
being similar to what are generally called Dutch loaves. Its upper 
surface is rounded, and of a dark brown, exactly agreeing in shape 
and colour to the upper crust of such a loaf; whilst its opposite 
surface is flattened, and of a paler brown ; bearing as perfect an 
agreement with the under crust : both the one and the other pos- 
sessing the smooth surface of the crust of a loaf. The intermediate 
substance, answerable to the crumb, possesses, in an extraordinary 
manner, the rough spongy appearance of the crumb of bread, being 
even separated by such clefts as might be supposed to have taken 
place in bread which had been dried by long keeping. The substance 
of the stone appears to the naked eye like a coarse jasper ; but, on a 
close examination, with the aid of a glass, the internal substance is 
discovered to be formed of very small white silicious stones, agglu- 
tinated by a silicious medium ; and the external part of brown sili- 
cious stones, connected in a similar manner : the substance of our 
seeming petrified loaf turning out to be actually a plum-pudding 
stone formed in some cavity, most probably left by the decomposition 
of some substance ; but what this substance had been, it seems im- 
possible to ascertain. The late truly respectable Dr. Gray, of the 
British Museum, thought it not improbable that this stone had 
formed part of the nucleus of an immensely large solen. 
The substances represented at Plate IX. Fig. 8 and 9, have ob- 
tained the name of petrified mushrooms : nor could the petrifaction 
of funguses produce a nearer resemblance to mushrooms than these 
substances present. They are frequently found in the cliffs in Dor- 
setshire, and other parts, and appear to have been formed by the 
gradual oozing of a soft ferruginous clay, strongly impregnated with 
pyrites, from small openings in the rocks. 
Yom*s, &c. 
