OF CORNWALL. 6 „ 
SeSls'n v thrOUgh ° Ut With a t dgbt ? eIW ° chre > and a little 
cneanous Clay : m water it would not diffolve, nor remain fuf- 
1 ° ded , but ,‘° r a iew minutes; when wetted, fluck fall to 
and coloured the fingers : I then ground it on a Hone with faff 
water and it made as good warm bejlo for drawing as that made 
ii'~t \ h !)™ e a fine foot y colour to paper. 
After this I ground it with Iinfeed oil, and upon laying it thick 
on the canvas, I found it mixed well with white, not at ah cracking 
or .lying off, and that it made a colour equal, and even fuperiour to 
burnt-umber, which, though a neceffary colour in painting, is very 
raw, harlh, and corrofive, and requires much Ikill to foften and 
correa its afpenties; and I am apt to think, that this natural 
Larth may with great fuccefs be fubftituted in its room ; when call 
into the fne, this earth made no more crackling than might be 
expefted from the air mclofed in a porous body: fprinklcd on a 
red-hot iron, it emitted no ill fmell : keeping it in die fire till it 
was red-hot it was not affefled by the magnet, either then or 
, vit 7 e ’ r but fcen ’ lng to hare acquired a little rednefs, I wetted it 
noth water yet found 1 it ft.ll to retain its tejlo and brown-umber 
colour. With aqua fortis it made not the leaft effervefcence I 
never faw but one lump of it : it is certainly a valuable earth for 
painting in oil, as well as in water-colours. 
"There are ftrata of clay for making bricks in fo many Diaces 
that there , hardly a parilh, feldom a large tenement SioC ,’ S “' 
though more generally found in the low and level lands than in the ' 
huly, and not fo often near the Hatty Soil as the loamy. Of white 
clays m Cornwall we have great quantities, and fome very ufeful. 
I he following are the moll remarkable which have reached my 
notice : A white clay there is found in the parilh of St. Agnes, 
which has been ufed for making tobacco-pipes; but either not 
proving fo good, or not fo eafily procured, (as it mull come from 
thence by land-carnage) it is at prefent difufed ; and in the Weftern 
iZTCt'L'SrS ' T 
In the tenement of Amalebreh, in the parilh of Tewidnek', 
twenty feet under the furface, there is a Jlratum of white clay. 
Immerfed m fair water, it imbibed the water fo greedily, that 
K “ a< f a h,m "8 effervefcence, diffolved eafily into a pafte, and the 
r 'kim ec ^ me ; after llirring, the land mixed with the clay 
Th 1 ] .^ 5 ^ Vin § ^ irce e ighths of the glebe fufpended in the water, 
arger lands or gravels were tranfparent, about the bignefs of a 
1 That is, belonging to St. Ewine. 
pepper- 
