6io Analyses oj Books. [Odrtober, 
Cape diamonds belongs to a horizon diredtly comparable with 
that which includes the Indian diamonds. 
The author considers it probable that diamond has been formed 
by crystallisation from a liquid hydrocarbon, the carbon having, 
according to Liebig’s views, been purified by the gradual elimi- 
nation of CH 4 . The experiments of Sir D. Brewster render it at 
least probable that the diamond must have been at one time in a 
soft state. The author thinks that the Koh-i-nur is the basal 
portion of the Great Mogul diamond. It has been suggested by 
native authorities that the original name of this stone was the 
Kollur diamond. “ Such changes, in which, while the sound is 
more or less retained, a meaning is acquired, are not by any 
means rare in Oriental languages.” 
Graphite occurs in various parts of India, and samples have 
been brought to England. Whether they will ever become of 
commercial importance, like that found in Ceylon, is open to 
doubt. In some localities a workable thickness cannot be ob- 
tained, whilst in others the mineral is contaminated with silica 
and iron. The former impurity, when occurring, renders graphite 
unfit for use in pencils and as a lubricant, whilst iron spoils it 
for the manufacture of crucibles. 
The only source of amber in India appears to be in Burmese 
territory. 
The next chapter treats of coal, peat, and petroleum. The rocks 
in Peninsular India, which probably correspond to the true carbon- 
iferous rocks of Europe, bear no coal : the useful coal of the Penin- 
sula is of Permio-triassic age. Beyond the Peninsula coal is found 
in more recent deposits. The coal-bearing areas of India are 
estimated by Mr. Hughes at 35,000 square miles, though it must 
not be supposed that workable coal exists everywhere in this 
region. Much injury has been occasioned by the carelesness 
and ignorance of persons who have undertaken to work the 
deposits. One of the plates represents a “ gin,” in which the 
motive power is supplied by — women ! 
A curious facft is here mentioned, i.e., that the operations of 
the coal-ring in 1872, which produced such disastrous results in 
England, did not perceptibly affecfi: the price of fuel at Calcutta. 
True peat only occurs in tropical regions in upland districts 
where the climate is substantially temperate. It is met with in 
the Nilgiris, and if rationally utilised might lessen that destruc- 
tion of the forests which has wrought such mischief in many 
tropical and sub-tropical regions. 
Petroleum is entirely absent in Peninsular India, but it occurs 
in Pegu, Arracan, Assam, &c. In the Punjab wells exist which 
a specialist, Mr. Lyman, estimates might produce 100 gallons of 
oil daily for eight years, after which the . supply would probably 
fail. It is noted that in India, just as in Pennsylvania, petroleum 
and brine springs occur simultaneously, — a fa< 5 l which seems to 
indicate that the formation of petroleum is in some unknown 
