10 
Burma, though many an anticline, apparently as 
well fitted for the storage of petroleum, has been 
examined and tested. Meanwhile no fewer than 
nine companies are engaged in a race for the 
deeper and richer oil-sands in the Yenangyaung 
field, and it would appear that the end cannot be 
far off. One may, perhaps, be allowed to express 
regret that steps were not taken by Government 
to regulate this competition until it had seriously 
affected the resources of the field; especially in 
view of the fact that Burma is the only country 
- directly under Imperial control which is known 
to possess large stores of petroleum, and that 
an adequate supply of fuel oil may become, in 
the near future, of vital importance to the national 
existence. 
1 
Pivad. tr Naty 
2 ve ee 
ag OS 
NATURE 
[SEPTEMBER 4, I9I3 
suggestive, as well as the affinity shown to exist 
between petroleum gas and such admittedly 
organic products as marsh-g’as and firedamp, in 
respect of the proportion of methane that they 
contain. The solution of the problem is one of 
great practical importance, for upon it depends 
the question whether an oil-sand, once drained of 
its petroleum, might ever recover its productive- 
ness. 1. A. eee 
OCEANOGRAPHY OF THE MEDITER- 
RANEAN.1 
THE Mediterranean Sea has always been an 
attractive field for oceanographical investiga- 
tion, since it presents many features which con- 
Yenangyaung—Native well-digger in diving dress. (The man on his right is holding the mirror used to illuminate the bottom of the wel.) 
From Memoirs of the Geological Survey of India, vol. xl., parti., “* Ihe Oil-fields of Burma.” 
In the final chapters of the work will be found 
an able discussion of the origin of petroleum, 
and of its relations to geotectonic structure. The 
difficulty of accounting for the presence of oil- 
sands above a water-bearing stratum (a by no 
means uncommon occurrence at Yenangyaung) 
on any theory of inorganic origin, which would 
entail an upward migration of the oil from a deep- 
seated source, seems to be insuperable; while, on 
the other hand, the arguments brought forward in 
favour of an organic origin, at least in Burma, 
Assam, and other similar areas, seem no less con- 
vincing. Though any direct geneti¢ relation be- 
tween coal and oil is expressly disclaimed, their 
close juxtaposition in those countries is highly 
NO. 2288, VOL. 92] 
trast strongly with those of the other enclosed 
seas. Italy, Sicily, and a submarine ridge over 
which the greatest depth of water is about 400 
metres, separate the whole area into two sea- 
basins. The western one, comprising the Balearic 
and Tyrrhenian Seas, is, for the most part, about 
2000-3000 metres in depth; while the eastern 
basin, which includes all the seas to the east of 
Italy and Sicily, is rather deeper on the average, 
and soundings of more than 4000 metres have ~ 
been made. Large coastal areas, like the North 
Sea, with depths of less than 200 metres do not 
1 Report on the Danish Oceanographical Expeditions of 1909-10 to the 
Mediterranean and Adjacent Seas. Edited by Joh. Schmidt. Vol. i., Intro- 
duction, Hydrography, and Se1-bottom Deposits. (Copenhagen, 1912.) 
Pp. 270+xx plates. 
