501 



of the British Association, viz. " The most abstract scientific inves- 

 tigations have often led to most useful industrial applications ; and 

 observations and experiments, seemingly trivial and likely to lead 

 to no useful result, have sometimes, after the lapse of years, been 

 elaborated into discoveries which do honour to human nature." 



Let us by way of illustration sketch some of the countless re- 

 searches which preceded the invention of the Electric Telegraph. 

 In 1729 Grey discovered that electricity could be transmitted through 

 conductors to a distance. In 1747 it was transmitted through seve- 

 ral miles of wire. In 1 753 an anonymous writer in the ' Scots' 

 Magazine ' first suggested the idea of an electric telegraph. In 1800 

 the voltaic battery was invented. In 1802 it was discovered that 

 the earth might be substituted for the return wire of a voltaic cir 

 cuit. In 1820 Oersted discovered the mutual action of voltaic con- 

 ductors and magnets, the foundation of the science of Electro -mag- 

 netism. In 1820, also, Schwiegger invented the electro-magnetic 

 multiplier. In 1822 Ampere developed the laws of Electro-mag- 

 netism, and discovered many new facts, and Arago detected the action 

 of a voltaic current on soft iron. In 1827 Ohm eliminated the laws 

 of the voltaic circuit. In 1832 began the brilliant researches of 

 Faraday, in which he discovered and enunciated the laws of voltaic 

 and magneto-electric induction. In 1834 Wheatstone invented and 

 practically applied a method of measuring the velocity of electricity 

 in metallic wires. In 1835 Gauss and Weber employed their electric 

 battery in establishing a communication between the Observatory of 

 Gottingeri and the University ; and in July 1837 Wheatstone first 

 tried his electric telegraph on the line of the London and Birmingham 

 Railway. During all this period the voltaic battery was gradually 

 improved and its powers vastly augmented by Daniell and Grove. 



Again, the progress of Chemistry during the last sixty years affords 

 abundant evidence of the advantages derived from the pursuits of 

 abstract science, when viewed simply in their bearing upon the com- 

 fort and convenience of mankind. 



At the close of the last century, the Swedish chemist, Scheele, 

 made a series of experiments on the black oxide of manganese. To 

 some this might have seemed a very unprofitable waste of time ; but 

 what was the result ? Chlorine was discovered, a substance of the 

 greatest importance in the arts. Berthollet, finding that this gas 



