MICHAEL FARADAY 251 



writing, and this soon led to his remarkable mastery of des- 

 cription, and also of giving experimental demonstrations. 



After he had thus tested his powers for about six years, 

 and received Davy's approval, the apartments previously 

 occupied by Davy in the Royal Institution building were 

 promised him, and he married when thirty years of age the 

 daughter of one of the Sandemanian elders, a goldsmith. 

 The marriage was a happy one for the whole of his life, but 

 no children came of it. 



Ten years of enthusiastic and many-sided scientific activity 

 now followed, of which we can only give a summary, 

 since this time, as we see when we look back, only formed the 

 introduction to his highest achievement, though its results 

 would be quite sufficient to make a reputation for any man 

 of science. To this period belong the researches carried, 

 out conjointly with Davy, on the liquefaction of gases. 

 Substances originally discovered in the gaseous state, and 

 hitherto only known in this state, such as chlorine, carbonic 

 acid, ammonia, sulphurous acid, hydrochloric acid, were 

 brought for the first time into the liquid state, a fact which at 

 the same time confirmed the conviction of the tangible and 

 ponderable material nature of gases, and of the unessential 

 nature of the state of aggregation, which only depends upon 

 temperature and pressure. Very extensive researches were 

 also carried on concerning steel alloys, and the production of 

 new kinds of glass.^ Faraday further discovered at this time 

 the hydrocarbon ben2ene, which has later become of so great 

 importance. 2 He obtained benzene by thorough investiga- 

 tion of a product obtained from the condensation of oil gas, 

 and most carefully determined its quantitative composition, 

 vapour tension, and many other properties. This funda- 

 mental investigation deserves particular mention to-day, 



1 See Faraday and his Metallurgical Researches, by Sir Robert Hadfield, 

 London, 1930; Nature (Supplement), Aug. 29, 1931. 



2 Philosophical Transactions of the Royal Society, 1825, page 440. 



