EARTHS. CALCAREOUS. J2. Spaium. 



79 



Found in the warm baths of Hungary^ Wijhadin., and other 

 places, often in luch quantities as to fill up the canals and 

 du<fts; more frequently white than tinged with any other 

 colour i is more or leis compaifl, and fomctimes To hard a^ to 

 receive a fine polifli. 



Cr€tttor, Confiding of very thin diaphanous fcales. 



Porus pulverulentus. Gerhard miner. /^•45' «• t. 

 Found principally in warm fprings, contaifiing cakareous 

 earth, on the furfacc of which it floats like a pellicle. 



^(jiaceus, Confifting of the aggregate fragments of lliells* 



1, Compa<fi and harder. 



Teitaceous Tufa. Kir^wan miner. %. p. 79, 



Found in the neighbourhood of 63^/2^2^/^, Palermsy and the pro- 

 montory of Pufioro in Sicily : white or yelJowifh -white, ex- 

 ceeding porous and brittle, formed of various fiiells brokers 

 and compa^led together* 



2. Softer and not compaft. 



Marly Tufa. Kir'Zt:an mineraL 1. /• i 8o« 



Found in moft parts of Europe^ yellowifh-white, rcfembHng 



mortar, without luflrc or tranfpaiency, ana very porous. ; 



frajflure earthy. 



12, SPATUM. Confiftlng of carbonate of llmc, a 

 larger proportion of carbonic acid gas, and wa- 

 ter: lamellous, fhiiing, parafitical, i'oit^ lighrifh, 

 breaking into rhomboidal fragments: crackling: 

 in the fire. 



at 



A. Of a common fgure, 



ofacum, Opake or nearly fo# 



Spatum Solubile. Syjl^ nat. xii. 3 p, 49. n. 5. 

 Spatum rhomboidale. Wall. fyji. min. \.p 137. «,i, 

 Spatum calcareum. Cronli. min<, feci, 10. 2. b. 



2. With che fragments irregular. 



Spatum calcarium. Syst. nat. xii. 3* ^, 49- ;;, 7. 



3. With a variable lullre. 



Spatum fugax. iyst. nat. xn. 3. /. 49 « 10, 



Common Spar. Kirtuan miner 1 p ^6. 



Calcareous .^par. Sch;r.eifier mtn. l. p. 220. 



Calcareous Spar. Thomjon chem. 1^ p 609. 



Found in "Nur^way^ SiDedev., Germany^ ^ivifzerlanJ^ and Huti" 

 garyy molt commonly white, fonietimes ciiicreous, blueifh, 

 greenilTi, yellowifh, red, or blackifh. The variety 3) changes 

 its luilre with refpect to its pofiiion in the light. 



