text:  The streets lighted by gas (which the Persian princes call "the spirit of coals") are described in terms of the highest admiration--"On each side as far as the eye could see were two interminable lines of extremely brilliant light produced by a peculiar kind of vapour here called gas which made the city infinitely more interesting to look at by night than by day; but the most extraordinary thing in reference to the flame in the lamps was that this appeared to be produced without the medium of either oil or wick nor could I discern the cause of the lighting