160 P. Gerald Sanford—Fuller’s Earth. 
It was probably to the action of these and other organisms in~- 
eliminating the silica held in solution in the sea-water, and after- 
wards to chemical action, whereby further precipitation of silica 
on and around that which had been previously secreted by the 
organisms, that these nodular masses had their origin. 
TV.—ANALYSIS oF THE FuLLERS HartH oF VRONGOCH. 
By P. Gzraup Sanrorp, F.I.C., F.C.S. 
OME four years ago I published in this Magazinu! an analysis 
of the Fullers Earth of Nutfield, Surrey. The Nutfield samples 
were given to me by A. Sheridan, Esq., C.E. I now wish to record 
the analysis of a large bed of this clay at Rhiwlas, Vrongoch, 
near Bala, N. Wales. The beds are about 60 feet thick, and are 
upon the property of R. J. Lloyd Price, Esq. In this case also, the 
samples were sent to me by Mr. Sheridan. ‘The two samples A and 
B are of somewhat different composition. B contains considerably 
more silicate of alumina and less alumina than A. A would of 
course, from a fuller’s point of view, be the better earth of the two. 
Although the Nutfield and Vrongoch earths are so similar in com- 
position, their appearance is very different: the Surrey earth has 
a greasy feel, a hard smooth surface, that can only just be scratched 
with the finger nail; the Vrongoch earth is soft and friable, dark 
grey in colour, and very earthy, and dissolves in water to the extent 
of about 4 per cent. of its weight. As regards the grease absorb- 
ing properties, the Vrongoch earth appears to be even better than 
the Nutfield samples. Fullers Harth appears to be an excellent 
material for cleaning chemical apparatus that is greasy, or soiled 
with fats and oils. 
Awnarysis No. 1.—Sampue A. 
Matter insoluble in acid= 78-27 per cent. consisting of ( Silica = 63°26 p.c. 
Alumina (Al203) = IPOH” 5. Ke,0; = 8°72)%,, 
Peroxide of iron (Fe203)= 0°42  ,, AlkO3 = 6°30 ,, 
Lime (CaO) = O83 4 
Manganese oxide = trace 18°27 
Magnesia (Mg(Q) = GD go° 
Sulphuric acid (SO;) = 031  ,, 
Alkalies (K20, Na.O) = 2°02 ,, 
Combined water = 88 op 
100-00 
Awnatysts No. 2.—Sampze B. 
Matter insoluble in acid = 78°53 p. c. consisting of ( Silica = 57°01 p.c. 
Alumina ioe ce Weeye an Fe.0; = trace 
Peroxide of iron ... = 860 a, 1 ALo; = 21-52 p.e. 
Lime emubeee = O80 >», 
Manganese oxide ... = trace 78°53 
Magnesia é = P30 55 
Sulphuric acid = (05 5, 
Alkalies OO, 
Combined water ... eS 4°78 99 
100-00 
1 Grou. Mac. Decade III. Vol. VJ, No. 804, p. 455. 
