226 ^'ic Philippine Juunial uf Science im 



horizon. That this is not simply marsh gas is, I believe, shown 

 by the analysis. 



Analysis of the gas collected by ]\'<illacc E. PraW from the Juniuuy well 



in 191 J.'' 



Per cent. 



Hydropcn 5.2 



Methane 89.4 



Ethane 0.0 



Carbon dio.\ide 0.6 



Nitropren 4.3 



Oxypen 0.0 



Carbon monoxide 0.5 



'Mineral licnourccs I'. I. lor 1912 (1913), 47. 



'' Analysis by Forrest B. Beyer, chemist. Bureau of Science. 



It is known, of course, that methane is the chief constituent 

 of natural gas and that ethane is usually found in it, but examples 

 are known where the latter is absent. The presence of hydrogen 

 and of nitrogen particularly seems to argue in favor of the 

 supposition that this gas is not merely a product of vegetable 

 decay. It is not impossible, of course, to have a marsh deposit 

 at almost any depth in sedimentary formations. The facts, how- 

 ever, that we have some considerable depth, presence of salt 

 water, and these extra constituents seem to make it highly 

 probable that this is natural gas and is associated with a 

 deposit of petroleum. As to the amount of oil likely to be pres- 

 ent in these formations we can only conjecture. 



As traverses were made along the streams in this part of the 

 island, close watch was kept for any oil seeps, but nothing was 

 seen even suggestive of the presence of oil. It is possible, of 

 course, that the oil is of so light a grade that on evaporation it 

 leaves no residue easily detected on the rocks and thus would 

 easily be overlooked. 



The sedimentarj^ formations are so folded that what oil may 

 be present would be collected into natural reservoirs. There 

 are indications also that sandy beds exist which would afford 

 sufficient pore space for the retention of any oil that may be 

 present. For these reasons we can say that it is not at all 

 unlikely that petroleum does exist in this island. 



GROUND-WATER RESOURCES 



The importance of an adequate supply of pure water in trop- 

 ical countries no longer needs any argument. The need for 

 a supply of uncontaminated water for the growing city of Iloilo 

 has become pressing. Several unsuccessful deep wells have been 



