'A 
ON THE BLACK LIMESTONE AT 
KAAfUNING, 
On the road liotireen Enggor (on tlui Poralc T?iver) and 
aud at about uiue miles fmtu the formor placo, is a 
picturesque limestone hill calletl Chanjjrkat Kaniuniii^^. It is 
]it^rhap8 some 600 to 800 feet iu heij^ht, aiul is eoiuposod nf a 
l>lack Iiniestt>iie differiuj^' rn many respet^ts from that of a similar 
eolonr found in other parts of the State. 
Tlie limestone is nearly black in colour, with occasional 
veins of pure white. It is soft and is easily cut with a knif* . 
yields a j^-rey powder» and has an uneven fracture, dull iu tli * 
direction of the ^ain and minntely siiarkliiig across ilie fjrain. 
It blaekens the hands when handled, and when rublxjd with a 
hard substance presents a poMshed lilack surface. In thin 
sections under the microscope it is seen to Ix? made up of while 
crystalhne carbonate of lime, enclosing? opaqiie black ah in in*:' 
scales and irregular masses, Wlien a fragment is \>nt into dilute 
acid the lime dissolves, leaviuf^ a black powder, whieh under the 
micTO&eo|)e presents the appearance, in miniatiiret of pieces of 
coke. The grains are of different sizes and very diverse shapes. 
The powder is shghtly gritty Iwtween the fingers, from admix- 
ture of a snuill amount of <]uart7. sand. The particles of this 
substance, Iw their appearance, suggest the idea that thev have 
lH?en in a plastic state and that the crystallization of the en- 
closing calcite giive them their present form. This is l)est 
shown in a decalcified section of the rock. 
The lilaek powder when rubbed on paper, or between the 
lingers, ]>rL?sent8 the characteristic appearance of plumbago, while 
bt*f(jre thf bloAvpipe it Ixdut^^is in the same way aH that subst^m^-^n 
and if ht-ated with nitre it deflagrates. It is therefore carbon 
in the fonn of graphite. 
