186 Dr Fyfe on the Comparative Value of Oil and Coal-Gas , 
4 
this, arises another question. Were the company to reduce still 
farther their charges, would it increase the demand and conse- 
quent profit ? There is no doubt it would increase the demand, 
for at present, owing to the high price, there is not much gas 
used, consequently part of the capital is lying dormant; where- 
as, were the price reduced, there might be a greater demand, 
which might enable the company to make the gas at a less price 
than they are now doing, consequently make the selling price 
less. But this would not operate to so great an extent as in 
coal-gas manufactories. In these the price of the raw materi- 
als is a trifle compared to the other expenditure, consequently 
by enlarging their work, the gas can be made at comparatively 
a less expence ; but in oil-gas works, the chief expence is that of 
the oil, and therefore in making a larger quantity of gas, though 
not requiring much more to be laid out in labour, &c. the out- 
lay for oil keeps pace with the additional quantity of gas re- 
quired. 
Notwithstanding I have thus given an opinion against oil-gas 
as now manufactured, I do not mean to assert that it never can 
come into competition with coal-gas. Oil-gas establishments 
are in their infancy, and, as it has been proved, that, by tire 
present mode of decomposing oil, there is a considerable loss in 
the illuminating power by converting it into gas, other more ef- 
fectual methods of decomposing it may be discovered, which 
will of course diminish the expence of the gas, allow it to be of- 
fered at a lower rate, and thus bring it into competition with coal- 
gas, provided zee consider it as having three times the illuminating 
power ; but if, as, I have endeavoured to prove, it is onlv 
about twice that of good coal-gas, I fear it never can come into 
competition with it. 
I cannot conclude these remarks, without publicly expressing 
my thanks to Mr Watson, manager of the Edinburgh Coal-gas 
Company, and Mr Forrest of the Leith Oil-gas Works, for the- 
information they have given me, on the expenditure and in- 
come of their establishment ; and for the assistance they have 
afforded me in enabling me to conduct the few experiments I 
have stated on the quality of the gases. 
