75 EARTHS. CALCAREOUS, n. Tophus. 
Qsieotolk, Catcarpous, more or lefs cylindrical, perforated, 
Phlofttph. TranJall.lj^^. p. 378. 
SyJ}. xat. xii. 3. />. 189. a. 6. 
Staladbtes calcareo arenofus, ff-'all, fyti, 3. p. 382, »,6. 
Found in variws parts of Germany, and elfewhere, both in 
brooks and under beds of fand, from the fize of a crow-quil’ 
to the tbicknefs of a man's arm : white or afh. colour, lome- 
ihing in the fbape of a bone, and was formerly fuppofed to 
have the quality of uniting Orokca bones. ft is mollly in 
long cylindrical pieces, fometimes irregularly tubular and 
porous, fometimes filled up with a marly earth mixed with 
fand, with often the remains of decayed root^ of trees in t^'e 
centre. The incraftaiions do not appear in regular concentric 
layers, but confill of thin ftrata fpir^ly rolled up: when firft 
found in the earth, it is foft and duffilc, but lu a yery fhort 
' time it hardens by expofure to the air : confifts of fand and 
eatth cemejitcd by a calcareous depofitiou, 
h.TttJtanj. Incruftitig animal and vegetable fwbftances with a cglca- 
reotts coating and affiiming their figure. 
Stalaflites vegetab. incruft. Syf/.itat. xii. 5. p, 183. ». l. 
Stalaaites calcareus. Wall fyH. min. 2. p. 380, a. 5. 
Stafaftitic T ufa. Kirii^mn mineral, t. p 1 So. 
hoqnd in various parts of SnaeJert, Germany, Italy, &c, clothing 
with a calcareous coat the fmallcr branches of trees, leaves, 
prickles, mofs, plants, crabs, eggs, birds and their nefts, 
preventing them from decay by defending them from the 
aftion of the atmofpheric air. Moft of thofe fubftances, 
which are commonly called petrifafiions, are of this fpe- 
cies. 
lebetutp. ificrufiing the bottom and fidps of veffcls, in which water 
has been boiled 
Tophus calcar, lebetum. Sffi xii. 3. 183. 12, 
Tophus fuftbilis. Wall, fi ft- min. 2 p. 392. ». ij. 
Found on the bottom and round the fides of Tea kettles, and 
other veffels in which water has been often boiled, forming a 
thip hard tncniftatioii. ft is formed in much greater quan- 
tities from fpring than from rain water, 31^ is feldotn with- 
out a portion of filica. 
Pentium. Forming incruf|aiions on decayed teeth. 
Found in fcales, plates or irregularly fhaped lamps on decaying 
teeth, and feems to be formed by depofition, in the fame 
manner as the cruft in tea-kettles. Its furface is very rough, 
and more or lefs porous. ® 
Covering the bottom and ftdes of the receptacles and canals 
of warm baths. 
Tophus calcareus grannlatus. Syjl. nal, xii, 3,/. i8g. n.i%. 
pbtrmalit. 
