BLACK LIMESTONE AT KAMUNIKO. 
20 
The rock has a sjsecific gravity of 2*66 at S4P and 
condists of — 
Carbonate of Lime „. 91 '4 
Carbon (graphite) ... ... 8*1 
Silica ... ... ... ... -5 
100-0 
Incliidiiig the carbon in combination with the lime, there is 
nearly 20 p(^r cent of that substance in the roek. 
When dry, the stone is a fairl)* good conductor of electricity, 
and it' a piece of it and a sUp of zinc are appHed to the tongue, 
the well-known sensation produced by the passage of a weak 
current of electricity will be felt. 
From the oceurrenee m the immediate neighbourhood of 
the up[)Or beds of the schistose rocks which underlie the lime- 
aUme foruJation of Perak, it would apjieur that the Kaniuniuju^ 
I teds l>elong to the lower part of the calcareous ficries. It should 
l»e stated, however, that the limestont' which rests on the under- 
lying beds, as far as has Ijccu observed in other parts of the 
Slate, is not carhonaceous. Whether this is a sign of un- 
conformity, *»r m simply due to local causes iu ojjeratitju at the 
time of th«' f Jejwsition of these beds, is, in the present state of 
our know led iuifjossible to determine. 
TitmeatoT i'S c jntainin^^ j^^niphite have been found in Canada 
imd ihc. nortlicini parts of the United States. These mv\iH nrv 
of the archccan i>iTlod, and it is in them that the much disputed 
J^amki Canmiejise occurs. 
In the schistose beds beucath the limestone, ^"rapbite hats 
been found at Batu Gajah, in the Plus ValU-y. near Tapah and 
ill Bernain. It is mostly dissen)inated in scales and grains 
throuirli the body of the rock, but at Batn Gajah there is a well- 
doliued vein of it. This vein was cut in making'- tho new road 
to Lahat, and more recently agiiiu iu sinking a well in the 
hospital grounds. 
A consideration of the eharaeteristics of these schistose and 
erystalline calcareous foi-mations seems to point coiiclusiv(?ly to 
thi'ir btdoutfin^^ to the archtjeau jteriod; and it may l.>e stated 
that llie vvhoiu uf Perak, where the granitiu rocks have not burst 
through and come up to the surfaccp is covered Ity l>eds of the 
Laurentian formation, as no rocks of less age are known to exist, 
except the very recent quaternary drifts and alluvial deposits- 
