si A S Y S T E M O F 
SECT. LXXXIV- 
B. Stone Marrow^ Liths^narga : Keffekil of the 
Tartars. 
I have given this name to a kind of day, 
•which, 
1. When dry, is as fat and Hippery as 
foap: but, 
2. Is not wholly diffufible in water, in which 
it only falls to pieces; either in larger bits, 
or refembles a curd -like mafs. 
In the fire it eafily melts to a white Or 
reddifh frothy flag, therefore confequently 
is of a larger volume than the clay was 
before being fufed. 
4. It breaks into irregular fcaly pieces. 
A. Of coarfe particles : Coarfe Stone Mar-- 
row. 
a. Grey, from Ofmundfberget, in the 
. parifh of Rettwik, in Dalarne, and 
is there called that is, fuller’s 
earth. It is mentioned in an account 
of Ofmundfberget, publifhed in the 
Tranfaclions of the Academy of 
Sciences at Stockholm, in the year 
17^9, by the BergVradet, or mine- 
mafter, Mr Tilas, 
i, Whitifli yellow, from the Crini 
Tartary, where it is called Keffekil, 
K IS anfwered, That they are found together in the fame beds 
fviih the porcelain clay : that they have all the fame ex- 
ternal fgns, and differ from it only in the colour, being red, 
brown, or black, in regard to the contained metal ; that 
they are more refraflory in the fire than any other martial 
clay I and that, though they may be reduced fo as to relemble 
a black or iron- coloured flag, they yet retain their form. 
