Weekly standard. [volume] (Raleigh, N.C.) 1858-1865, 1863-06-17

DeSlucS Iuc DdCC86uICdtoo1 su0 VhAy NS6ASS VIII
ferred at this Commencement was that OF A. NJ. on
Mr. John B. Lynch of Mecklenburg county, Va, "a
graduate Of the University at the famous Commence
ment of 1859.
For the Standard.
No.2.-Clay, its Origin, Composition, Uses, etc.
BY E. EMMoNs, STATE GEoLoGIsr.
Kaolin; or as it is sometimes called china clay,
and sometimes also petuntre, is derived directly
from the felspar of granite, granite compounds:
We may learn how this happens byAeference to
the composition of felspar: thus, the purest form
of this mineral consists of slick, $3.50; aumine,
Water charged with carbonic acid seems to be first
absorbed, and the result of decomposition is an n.y.
drous silicate Of atumina or silica 40, alumina A,
water l5 the original felspar is AMBIGUOUS, or des
titute of water Part of the siica set free, is re-
moved in combination with potash.
1t is worthy of remark here that combinations
in the act of breaking up, are free to form new
bodies they possess in the instant of breaking up
power to act upon and combine with the bodies in
nascent state; one in which their combination
gives new birth to bodies If the nascent state is
passed, and the new birth is unconsummated, the
force or power of combination is lost Thus, we
may undertake to force union of silica with alum
ina BY forcibe contact by attrition in mortar the
result is only simple mixture In the decompo-
stion of fespar several minerals may also be form
ed crystals Of quartz or the more beautiful gem,
OPAL by combining with the proper proportion Of
water.
Kaolin is white in state of purity; it coheres
only slightly and is destitute in part of the plastci.
ty of other clays. 1t is often mistaken for chalk,
and its beds are generally known as chalk beds
Being derived from granite, it is in immediate con-
nection with the parent rock, and for the reason
that granite region is more or less elevated, we
must look for Kaolin only among the granite hills
Of district. 1t is distributed in this State in this
way: The search for porcelain clay in the lower or
Eastern district, WOULD u unsuccessful; but west
of Raleigh, 1t would be in its geological position,
and wherever granite and its allied compounds oc-
cur, may probably be found.
Kaolip derives its importance from its nfusibility
or its persistence unchanged in the ntensest heat
of the furnace, and when mixed with more fusibie
bodies than ITSELF becomes by its semfusion a
translucent body, still remaining pure white,
graysh or milk white. In England the finest clay
for porcelain or chinaware is in Cornwall, wheret rs
obtained by running stream of water over the de-
composing beds Of granite which carries with it the
finer and pufer particles Of the clay, and is finally
received into ponds tanks where it is allowed to
subside The fine sediment is removed, and after
being exposed to the atmosphere or months, is
ready for use. This clay, when it has been dried
at the temperature of2l2 deg. Fab, consists Of
Slick, 1882
Alumine, 1874
Prot oxide Of iron, OPT
Lime, O.36
Magnesia, GA
Water, 1857
The foregoing will serve for comparison with the
North Carolina Kaolins. 1t is not however, to be
inferred that the best cays of this class possess
uniform or fixed composition.
The most celebrated Kaolin of France is found at
Limoges, and consists of sick, 1907; alumlne 81
Go; water, 1917, with traces of lime, magnesia and
potash. 1t is plain, however, that as clay is pro.
duct of decomposition, its constitution depends
much upon the state of change which it has under
gone, especially with respect to lime magnesia and
potash, for these bodies ultimately disappear from
the mass produced.
The beds of Kaolin of North. Carolina are nu.
merous, and give US foundation to hope that they
will become important in the manufacture of fine
pottery ware. The finest kinds occur in Macon,
jackson, Buncombe, CstawLa and Chatham coun.
ties-the coarser in Wake, and on the western Dor.
der of Johnston county.
The jackson and Macon county Kaolns are snow
white, friable or fall to powder readily, but form
with water semi-plastic mass which, on driving is
tender or easily broken. Heated to bright redness
in the furnace it is still white and when raised to
an intense white heat is still infused and white
These experiments with all the clsys were CAREFUL
ly executed by my Assistant E Emmons, Jr., to-
gether with many other trials to test their value
for crucibles and friedrich. The jackson CLAW is
composed Of slick 40, alumine 800, water II;
iron lime and magnesia, none or mere traces. The
kaolin of Buncombe county is composed Of slick
400, aumine 800, water 100; that Of Chatham
county, slick $50, alumine $40, water ITO; lime,
iron and magnesia, none. The latter dissolves and
gelatinizes in muriatic acid 1t is white, compact
and infusible and in fine, is the most perfect Kaolin
we have yet seen On comparison with the Corn
wall AND French clays it will be seen that they close
ly resemble them and each other in their compost
%
the finest porcelain seeing that their behavior when
subjected to heat confirms the inference We have
made.
DEsERTER SHoT.-Followirg in the rear Of, and
hnlOnOino n tho which