382 Scientific Intelligence. [May, 
POSING Shue teas 2 FE Nace a 5. 6 ars « 43°32 
ATUMING. oe sn 5 6 Sore ee elie es 6 5, OUD 
Gicinay. Sip. oh eee otal ois atin issue us Pe 
Cmte OF MUN... ee akan seen s it RE oe 
CURTMe ON CHIC eo oe che oe eT ease NS a wee Un A 
98°58 
Hence it is a compound of one atom of silicate of glucina and 
two atoms of silicate of alumina. 
VI. Crichtonite and Elba Iron Ore. 
The mineral called crichtonite by Count Bournon has been 
ascertained by Berzelius to be a titaneous iron. As this mineral 
has a peculiar metallic brilliancy similar to that of iron ore from 
Elba, it occurred to Berzelius that the Elba iron ore probably: 
contained titanium also. An analysis of it soon satisfied him 
that this opinion was well founded. 
VII. Potter’s Clay near the Halkin Hills, Flintshire. 
In the number of the Annals for March, p. 233, the discovery 
of this clay was noticed, and likewise the circumstance of its 
being adapted forthe manufacture of stone ware without any 
addition. I have received a very small specimen of the clay, 
sufficient, however, for a chemical analysis; and I shall here 
state the constituents which I found it to contain. Its charac- 
ters being the same with those of potter’s clay, it’ seems needless 
to give any description of its appearance. Indeed the minute 
specimen which I have in my possession would not enable me to 
give its characters with much precision. Its constituents were 
as follows : 
SME. ois arsine oie 14-400). o:6.<.2. fies! hen GIO 
APE 5 sive wees LOD. s.0.5:0.650 deie.s ae 
Oxide. of iron..:..... O°500. - +» <wlawrae outer 
Fem Ss aa:s so eer ee bond ie aaa bs seb 
WEIS, "ees's. ccd, . OTN Ae oihem eh dio sa 
23°855 95°42 
It appears from this analysis that the clay in question contains 
a considerably smaller proportion of alumina than potter’s earth 
usually does. Notwithstanding the two per cent. of oxide of, 
iron which it contains, it may be exposed to a strong red heat 
without losing its white colour. This property of retaining its 
colour, when heated, is essential to every clay which is to be 
used for making stoneware. 
VIII. Persulphates of Iron. 
In consequence of Mr. Cooper’s paper on the persulphates of 
iron in the last number of the Annals (p. 298), which contains’ 
