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escape of gas into the apartment, but from the burner itself burst- 

 ing into fragments like a shell, and scattering destruction around. 

 Electricity, now destined, partially at least, to supersede it, was but a 

 toy on the lecture table in the shape of a glass cylinder and a Leyden 

 jar; and even when, years after, the law of induced magnetism 

 and secondary currents was discovered, their only effect for a long 

 time was to fill the shop windows of instrument makers with 

 vermiUion coloured revolving magnets ; till, by slow degrees, the 

 powerful dynamic machines came into use as means of light, and, 

 perhaps, power. 



The means of conveyance were only an occasional stage coach 

 or the clumsy hackney, which seemed then sufficient for the want 

 of the time; but what else than steam and the iron road could 

 bring to the centre of industry and business the crowds that now 

 throng the City in the day, to disappear at night — absorbed by 

 the continually expanding area of the Metropolis? Nearly 50 years 

 ago I saw the first model omnibus paraded between the Bank of 

 England and the Royal Exchange for the inspection of its future 

 customers. Stand now on the refuge between Princes Street and 

 the Mansion House, and look around you ! 



It seems to me that it is in Chemical Science the greatest com- 

 parative advance has been made, because — as in Mathematics, Euclid 

 is still an authority, and the laws of Mechanics must have been 

 known to the builders of the Pyramids, and Astronomy to the 

 Chaldeans — Real Chemistry is comparatively modem, though on 

 the collapse of Alchemy some few facts remained, I might almost 

 say stumbled upon, by the searchers after the Unattainable ; and 

 even in a Dictionary of Chemistry, translated from the French, which 

 showed a marked progress, many pages are devoted to an article on 

 " Phlogiston," that convenient principle by which the chemists of 

 that day accounted for everything they could not understand. 



It is in the spirit of investigation which governs the researches 

 of our day, that such a marked progress is manifested. We cannot 

 imagine Davy, Faraday, Huxley or Tyndal, when they observed that 

 iron, for instance, changed its formation by exposure to the air, 



