112 NATURAL SCIENCE [August 
London) on behalf of the Railway Company. He reported to the 
Company that the lignite contained :— 
Moisture . ; ‘ . . , 4°90 
Volatile matter : . : 4 . 15°55 
Fixed carbon 5 A F : ‘ 1°74 
Ash. é . : = ; 3 77°81 
100°00 
This record I take it is about the usual result of the analysis of 
lignite, and I fear throws very little light on the subject. 
The greater probability seems to be that the gas is derived from 
either the Purbeck Beds or the Kimmeridge Clays by percolation 
through the comparatively porous strata above. The Purbeck beds 
are known to contain a certain amount of petroleum and bituminous 
matter, one bed being particularly rich; but far richer deposits are 
in the deeper lying Kimmeridge Clays, immediately above which Mr 
Henry Willett discovered the gas. 
This matter, however, as also the subsidiary one of the associa- 
tion of petroleum, is one which can only be determined satisfactorily 
by means of a deeper boring. The Heathfield borings are much 
shallower than the bulk of those in North American gas wells, which 
not uncommonly exceed 1000 feet. The gas which occurs in so 
many of these American wells is usually the forerunner of a spring 
of petroleum, and it is possible that the occurrence of gas in large 
quantities at Heathfield may indicate that there is a larger supply of 
oil in the petroleum-bearing strata beneath than has been before 
known to occur at the same horizon in other places. 
Dr Hewitt has also reported to the Railway Company on the 
gas, which, he states, is composed of three constituents :— 
Marsh Gas . : : . ; 91-90 
Hydrogen . ; é . . 7°20 
Nitrogen . : : : : , “90 
100°0 
The first two of the above gases, it may be remarked, are in- 
flammable, but burn only with a blue non-luminous or comparatively 
non-luminous flame. Nitrogen is not an inflammable gas. It is 
clear, therefore, that there is nothing in the analysis which can 
account for the illuminating power of the natural gas at Heathfield, 
for it burns with a brilliant yellow flame. The gas when burnt in 
an ordinary ‘ batswing’ or ‘ flat flame’ burner is so luminous that 
the casual observer would not remark the difference between it and 
ordinary household gas (although the difference does actually exist). 
Therefore we must suppose either that some luminous property in 
the gas did not present itself in the sample taken away by Dr 
Hewitt, or else that some variation has occurred in the constituents 
