Petrefaclion found at Eaft Lothian. 47 
they grow; but yet are convinced they are nouriftied 
by means of the falts and particles of matter conveyed to 
them by water and vapour, and that iron is a neceffary 
ingredient in their compofition ; fo I am perfuaded we 
ihall, at length, perceive (notwithftanding the general 
/ 
opinion to the contrary) that even ftones and marbles are 
ffill continually forming in the earth for the fervices of 
human life, and to fupply the continual wafte and decay 
that there is of thofe fubftances; and that the confolida- 
tion of them is effected by means of water and vapour 
likewife (of which I am able to produce very many and 
convincing proofs); and that iron, which is what alone I 
With now to make apparent, is unqueftionably a princi- 
pal means of effecting the induration of many of thofe. 
bodies. 
But I would not willingly trouble the Society with this 
paper as a matter of mere fpeculation. I would with that 
feme hint, which might be more immediately ufeful, 
fhould, if poflible, be derived therefrom; and fuch has 
been fuggefted to me by Dr. fothergill. 
If iron and the folutions of iron do thus contribute to# 
the induration of bodies, fuch folutions muff probably 
have that tendency in every ftage of thofe bodies’ exift- 
ence; and therefore it feems likely, that the fine, orna- 
mental carvings in Portland, or other ftone, might be 
much; 
