VALUABLE SECRETS LOST TO MEN.

Otago Witness, Issue 2812, 5 February 1908, Page 80

VALUABLE SECRETS LOST TO MEN.

The recent' attempt of a French savant, Professor Bordas, to convert the mineral known as corundum into rubies and sapphires by means of radium, recalls the fact that, t although there are at the present time a dozen different methods of making artificial diamonds, none of the stones produced by these methods can compare with those made of old French paste, the secret of which is lost. So perfect were paste diamonds that it was difficult for even a person with expert knowledge of diamonds to tell that they were artificially produced, whereas most of the modern artificial diamonds can easily be detected,. . and their durability is nothing like so great as the old paste diamonds ; indeed, good paste diamonds are now almost as valuable as real diamonds. ' Probably not one out of every 10,000 buildings standing in all parts of the world and built_ " : by 1 modern masons will still be (standing 500 years hence. We do not know how to put stones and bricks, together as the -ancients did, and consequently the buildings we raise -nowadays are really mere t^poL-_ : porary structures, and -will,-be in ruins" ! when the ancient buildings of Greece and Italy, which were built thousands of years ago, are in as good condition as they are now. Phe secret yis not in the bricks or in the stone, but in the cement and mortar. In modern buildings these essentials are the weakest points; in the buildings which the Romans and Greeks raised, the cement and mortar are the strongest points, and . hold good while the very stones they bind together crumble away with age. i Chemistry, we might imagine, is . ,the science which, has made the greatest strides during the last five or six decades. Yet modern chemists cannot compound such-^ dyes as were commonly used when • the great nations of to-day were still unborn. Now and again it happens that searchers after antiquities come across fragments of fabrics which were dyed thousands ( of - years ago, and they are astonished by the wonderful richness of the colours of the cloths, which, despite their age, are brighter and purer than anything we can produce. Just a3 the secret of dyeing has been lost, so has the secret of preserving the colours of' artists' paints, with the result that the pictures of modern artists will be colourless when many of the works of ancient masters are still bright. Yet the secret, which is as difficult to rediscover as that which lurks in the mystical notes of a Stradivarius violin, was known t*tf every ancient artist, for they all mixed their own colours. How to make durable ink is another great secret we" have lost. Look at .any letter five or ten years old and you will probably notice that the writiag has faded to a brown colour and is very indistinct. Go to any Trig museum/and you will find ancient manuscripts, the writing on which is as black and distinct as if they were written the day before yesterday.