MABERY. — COMPOSITION OF PETROLEUM. 



297 



clogging the wells by loose material, " shooting " the wells after boring 

 is not practised. The flow from the wells is irregular; frequently it 

 will amount to 300 barrels a day for a week, and then stop, and the oil 

 must, be pumped. 



The oil territory in Japan includes the following fields: — Amaze, 

 Nagaoka, Niitsu, and Hiyama. The different sections of the oil terri- 

 tory may be classified as follows: — 



Amaze \ 



Miyagawa \ green oil 



Gendogi ) 



Hirei ) 



Kitatani > dark oil 



Katsudo ) 



Koguchi ) 



Kusodsu ) 



Hiyama { Hiyama } dark green oil 



Amaze 



Nagaoka 



Niitsu 



The Amaze field is the oldest ; the Hiyama field has been most re- 

 cently developed; both these oils contain paraffine. 



The crude oils from the different fields differ essentially in their prop- 

 erties, as shown by the different specific gravity, the different percentages 



