514 Professor W. C. Boherts- Austen [Feb. 5, 



That was the effect expected from the transmuting agent, but do 

 not think that the attempt to produce gold arose entirely from the love 

 of gain. The colour of gold and purple impressed men strangely, 

 and the search for the transmuting agent was most eagerly pursued in 

 times when people lived for art, in a dream of colour. The effort to 

 find the secret of the tint of gold is due to the same impulse which 

 made the French in the thirteenth century manifest a keen " sensitive- 

 ness to luminous splendour and intensity of hue," so that, as Sir 

 Frederic Lcighton tells us, " a stained glass window, by Cousin, was 

 limpid with hues of amethyst, sapphire, and topaz, and fair as a May 

 morning." The chemists were able to stain glass ruby and purple 

 with gold : why should they not impart the same glories to metals ? 

 I could not hope to interest you in what follows, did I not call artists 

 to my aid ; and many will remember the glowing words Mr. Ruskin 

 uses,* calling purple a " liquid prism and stream of oi3al," reminding 

 us of the crimson and purple of the poppy, the scarlet and orange of 

 fire and the dawn. No wonder he chides us with turning the lamp 

 of Athena into the safety-lamp of the miner, and with getting our 

 purj)le from coal instead of, as of old, from the murex of the sea ; 

 *' and thus grotesquely," he says, " we have had forced on us the 

 doubt tljat held the old world between blackness and fire, and have 

 completed the shadow and the fear of it by giving to a degraded form 

 of modern purple a name from battle — ' Magenta.' '* 



You will remember that Faraday showed that gold, when finely 

 divided, is brilliantly coloured scarlet and purple. Here is a solution 

 of chloride of gold. Add a little dissolved phosphorus, and the gold 

 is precipitated in an extremely fine state of division, which tinges the 

 solution crimson, but if you try to remove this suspended gold you 

 will only gain a brownish mud. However, I will give you the secret 

 by which any one who possesses a blowpipe, a bead of gold, and a 

 fragment of one of the most widely diffused metals, aluminium, may 

 stain gold purple through and through. But if you add aluminium 

 to molten gold, you obtain many things, as this coloured diagram 

 and series of specimens show. [This diagram cannot be reproduced 

 without colour.] 



The series of specimens showed that as the proportion of alumi- 

 nium is increased, the golden colour of the precious metal is lessened, 

 and when an alloy is formed with about 10 per cent, of aluminium, 

 the fractured surface of the mass is brilliantly white : from this point 

 forwards, as aluminium is added, the tint deepens, until flecks of pink 

 appear, and when seventy-eight parts of gold are added to twenty-two 

 of aluminium a splendid purple is obtained, in which intensely ruby- 

 coloured opaque crystals may readily be recognised. Then, as the 

 quantity of aluminium is still further increased, the alloys lose their 

 colour, and pass to the dull grey hue of the aluminium itself. Per- 



The Queen of the Air,' ed. 1887, p. 129; •Times,' December 11, 1891. 



