INVENTIONS AND DISCOVERIES. 



motive engine is moved to the 

 front. This is the steam-horse, 

 which has drunk a thousand gallons 

 of cold water to prepare him for his 

 journey, and taken in provender 

 to the extent of one ton of fuel. 

 The engine-driver takes his place, 

 and opens a valve, the steam enters 

 and commences its work, the en- 

 gine works, the train follows, and 

 in a brief space, at the rate of 

 forty, fifty, and even sixty miles 

 an hour, it rushes through tunnels 

 which have been cut for miles in 

 the solid rock, along embankments 

 which have been piled up in the 

 valleys, over morasses whose pro- 

 foundest depths have been fathomed 

 and piled, through cuttings on the 

 sides of mountains, along precipices 

 with the ocean lashing their bases 

 across viaducts, over rivers and 

 ravines, crossing arms of the sea 

 by means of tubular bridges of 

 iron. "While the train is almost 

 on the wing," observes Sir F. B. 

 Head, "beating the eagle in its 

 flight, the passengers are reclining 

 in^ their easy-chairs, thinking or 

 .sleeping, reading or writing, as if 

 they were in their own happy 

 homes safer, indeed, than there, 

 for thieves cannot rob them by 

 day, nor burglars alarm them by 

 night. The steam-horse starts nei- 

 ther at the roar of the thunder- 

 storm, nor the flash of its fire. 

 Draughts of a purer air expel the 

 .marsh poison from its seat before 

 it has begun the work of death, 

 and, surrounded by conductors, the 

 delicate and timid traveller looks 

 without dismay on the forked mes- 

 sengers of destruction, twisting the 

 spire, or rending the oak, or raging 

 above the fear-stricken dwellings of 

 man." 



The Atlantic is now crossed al- 

 most every week from January to 

 December, and the passage seldom 

 lasts beyond twelve days; insomuch 

 that the merchants of Liverpool on 

 the one side, and Boston and New 



York on the other, calculate to an 

 hour on the arrival of the steamer, 

 and are seldom disappointed. 



LAVOISIER'S DISCOVERIES AND FATE. 

 Lavoisier proved that the fixed 

 air (carbonic acid) of Black was a 

 compound of carbon and oxygen; 

 that atmospheric air consisted of 

 oxygen and nitrogen ; and that 

 oxygen was the agent in combus- 

 tion and respiration, as well as in 

 the process of oxidizing metals, and 

 in the formation of acids (the acids 

 formed by hydrogen being then un- 

 known to the science). Lavoisier 

 thus generalized the discoveiy of 

 Priestley, and superseded the phlo- 

 giston theory by that of oxygen. 

 Lavoisier's theory of combustion, 

 if we may be allowed the meta- 

 phor, kindled the torch which has 

 lighted succeeding chemists along 

 the path of discovery. Lavoisier en- 

 joyed the privilege rarely awarded 

 to great discoverers in science of 

 seeing his views speedily adopted 

 throughout Europe. Such, also, 

 we are reminded, was the reward 

 of Hervey, who, after suffering 

 years of obloquy and persecution 

 for promulgating the doctrine of 

 the circulation of the blood, had 

 the satisfaction of living to wit- 

 ness his principles taught in all 

 the medical schools of the civilized 

 world. But, less fortunate than 

 Hervey, Lavoisier was persecuted 

 by more unrelenting men, who 

 struck him down in the heyday of 

 his scientific reputation and use- 

 fulness. During the French Re- 

 volution, he was thrown into pri- 

 son on a charge of adulterating 

 tobacco, factitiously brought against 

 him as a pretext for confiscating 

 his property. He became a victim 

 of the guillotine in 1794 "A me- 

 lancholy proof," Mr. Whewell re- 

 marks, "that in periods of political 

 ferocity, innocence and merit, pri- 

 vate virtues and public services, 

 amiable manners and the love of 



