EARTHS. ARGILLACEOUS. 3i.Argnia. 113 



i^ Tn a powdery form. 



Marga porcellana. J'P'all. min. 23. 

 Argil la porcellana. l^ogel miner. 33; 



3. Mixed wirh micaceous particles, 



Argilla porcellana. ^yst, nat. xii. 3. f. 200. n, 3. 

 Found in Cornixjally Japan, China, Saxony, and various parts of 

 Europe, and is luppofed to originate from decompofed felfpar: 

 colour white, greyilh, reddifh or ycllowifh-white : adheres 

 very flightly to the tongue, and feels foft but not greafy : 

 does not change its colour when expofed to heat, but becomes 

 white, and tranfparent in proportion to the quantity of filica 

 it contains: it is principally ufed in the manufafture of 

 china ware; contains alumina 60. iilica 20. air and wa- 

 ter I 2, 



Leucargih Very foft and greafy to the touch, adhering to the tongucj 

 ^<i* Ihining when rubbed, becoming firfl: blackiih and paler 



when burnt, apyrous. 

 Argilla apyra. Syli. nat, xii. 3. />. 200./?. 2. 

 Argilla apyra. Wall.fyst. min. i. p. 53, «• 10. 

 Potiers clay. Kirnvan mineral. I. p. 187. 

 Pipe clay. SchmeiJJer mineral, i. p. 156. 

 Common clay, Thcmfon chem. 3. /. 535. 



Found in Normandy, ne^r Cologn, Livonia, aiid Other parts of the 

 world: colour varying from pure white to black, and is often 

 variegated : when firit expofed to heat, it becomes blackifh, 

 from the inflammable matter it often contains^ but by conti- 

 nued heat it turns pure whit«: it is ufed for tobacco-pipes 

 and various vefiels. 



tithotnar- Friable, very greafy to the touch, lliining, fcaly. 

 .ga^ Talcum fubfriabile. Syd. nat.yiu.. 3. ^. 51. «, 1, 



Lithomarga. Kir^w an miner, i.p, 187, 



Lithomarge. Schmeiffer miner, 1.^.160, 



Potters' clay. Thomfon chem, 3. p, 535, 



2. Somewhat friable, green, making a mark. 

 Talcum viridans, Syji. nat, xii. 3. /. 51, «. 1. 



3. Hardi receiving a polifh. 



Terra miraculofa. Schuz. No'v, Ad, Ac. Caf, Nat. Cur, 3. app^ 

 Indurated Lithomarge. SchmeiJ/er 7nineraL i. /. 160. 



4. Emitting phofphorefcent fparks in the dark, when rubbed with 



the point of a pen. 

 V. Trebra Chem. Ann, 1784. i,/>. 387. Kirvjan l./. 190. 

 Bruchmann Chem. Ann. 1785. 1,^.449, 

 Indurated Lithomarge. Schmeifur min. i. /, 160. 



VOL. VIL — P 



