L 24 3 
I. PETRIFACTIONS are the parentF, and not the offspring of 
calcareous thotintains ; lince all caljt originates from animals. ' 
The bodies fubjedf to p6trifadion are folid, as fliells, bones, and 
woods. 
Succulent bodies deliquefce and corrupt, before Ilony bodies can 
harden. 
They occur in every part of the globe wherever calx is found • and 
are fotind in the highcft mountains of Peru. 
The materials producing pctrifaftion ait various. 
Calx by its calcifying power changes other bodies into a calcareous 
fubflancej e- gf- Schill into Marble ; It. IVgoth. Silex is 
connate with Calx, and in like manner exhibits petrifaftions. 
Vitriols by ferrimiination cohglutinate and penetrate : the Tophus 
marihus and feme others frequently contain (hells. 
Schift from foil or fand often prefents the veftiges of impreffed 
fubllances before its coalefcence. 
r 
Amber is not with' propriety brought under this head, fince it mere- 
ly contains and preferves from corruption, bodies formerly in- 
clofed within its relin. 
The modes of petrifaition are. 
By tranlubflantiation, where the whole material is preferved in its 
original form. 
By redintegration, where the original fubftance is worn away bf 
age, and the cavity filled up by laifidefcent material which pre- 
ferves its ancient form: Hyftcrolith. 
By imprellion, where the petrifying body receives and retains the 
figure of fubllances impreffed upon I't. 
By incruilation, after the manner of Stahaite, from calcareous 
water, particularly that of warm fprings : but thele will hardly 
come under the denomination of petriraAions, fince the fame 
things may be effeded at pleafure by art or the injedion of bodies. 
Fofiils, generally fo called, are Ihclls or bones deprived of their 
gluten by age: tellaceous fubllances, Jlihophytes, woods. 
