A DIFFERENT KIND OF WORLD.

Dominion, Volume 6, Issue 1675, 15 February 1913, Page 15

A DIFFERENT KIND OF WORLD.

SIR, J.DEWAB ON - VALUE OF. '■~;;,•/, OLD STOKIES.', ■_: Professor-Sir James Dewar.deliveredtko' first of a rcrie's of Christmas lecture epilogues at the; Royal Institution-: recently. The subject was alchemy'.:',;<■>:.■.■:■■"'•.'•■ _It was>ore ;thah.. a third''otiti-century,' Sir James" said, since ha had'delivered his first lecture on chemistry, and as the time paiscd they must all quit tho stage and leave the work to younger hands. He noticed-that'in. the young there .was a strong .tendency not' to : rovero 1 the. old stones that ho had 'enjoyed in the past. It was a different kind of world that they lived in; and,it was a pity, because the old , stories and' the way in which knowledge had been acquired were of infinite importance to,the young mind.- It gave them an incentive to labour and to enjoy their labour. -" . • ' i The .oldest chemistry' inoluded what little was known of the, chemical orta of the Indians, Egyptians.' Hebrews, and other, nations, of antiquity. They. could only judge of those from''.their motnls, glass, colours, and other antiquities, •: The alchemists belonged to the'middle ages, of European history. The Egyptians knew something about the blowpipe,' which was brought about \by!.the'-imitation;-'of .the orpins of -, respiration.' '■■•: ■■'■ '.. Throughout his lecture, Sir James conducted , a .number of elementary experi,merits, whichwero watched with tho'keenest interest ty a large audience, iri'whichchildren were well represented.- He showed, for example, how the ancients managed to pass through the ordeal of firo unscathed. To imitate the ordeal of passing through boiling load, an ingot'of lead was raised to boiling point, and nn attendant, by merely wotting' his hand beforehand, was able to scatter tho molten stream in showers with his baro hand. The experiments showed that the heat first oxpended itself in drying up the moisture before the operation of burning commenced./ An iron bar at ..white heat and a bar of sulphur wcra fused together to make a third compound different.from either. This 'illustrated .the • composition of the ores of various metals found in Nature. The experiments of the old alchemists in tho transmutation of base metals'into gold'.and silver-were explained.. By rubbing 'mercury,oh a plate of copper,' silver was apparently produced. In the samo, way a film of gold could be formed on-a plate of lead or iron, A liquid,-'having; been touched-with a certain salt, becamo:a solid, and by reversing 'the processes,- solids were turned back, ajaia into 'liquids.