HAPPY ACCIDENTS.

New Zealand Tablet, Volume II, Issue 77, 17 October 1874, Page 11

HAPPY ACCIDENTS.

The cracking of a picture placed in the sunshine set Van Eyck experimenting to produce a varnish that would dry in the shade. He found what he sought, and found beside that by mixing it with hia colors they acquired greater force and brilliancy, and required no subsequent varnishing ; and so came about the discovery, or re-dis-covery, of the arc of painting in oil. Mezzotinto owed its invention by Prince Kupert to the simple accident of a sentry's gun-barrel being rusted by the dew. Henry Schanwurd, a Nuremborg glass-cutter, happened to let some aqua-fortis fall upon his spectacles, and noticed the glass was corroded and softened where the aqua-fortis had touched it. Taking the hint, he made a liquid accordingly, drew some figures upon a piece of glass, covered them with varnish, and applied his corroding fluid, cut away the glass around his drawing, so that when he removed the varnish the figures appeared raised upon a dark ground ; and etching upon glass was added to the ornamental arts. Alois Senefelder, playwright and actor, thinking it possible to etch upon stone in lieu of copper, polished a slab for the purpose. He was disturbed by his mother coming into his small laboratory with a request that he would jot down her list of things for the wash, as the woman was waiting to take the basket away. There being neither paper nor ink handy, Seneielder scribbled the items on his stone with his etching preparation that he might copy them ut his leisure. Some time afterward, when about to clean the stone, he thought he might as well see what would be the effect of biting the stone with aquafortis, and iv a few minutes saw the writing standing out in relief. Taking up a pelt-bull charged with printing ink, he inked the stone, took of a few impressions upon paper, and he had invented lithography. The pelt-ball used by Senefelder was long indispensable in a printing office. A Salopian printer, in a hurry to get on with a job, could not find his ball, and inked the form with a piece of suft glue that had fallen out of the glue-pot, with, such excellent results that hetheneeforth discarded the pelt-ball altogether, and by adding treacle to the glue, to keep it from havdeniuii, hit upon the composition of which printer's rollers have ever eince heeu made. Three very different discoveries are recorded to have resulted from the unintentional application of intense heat. Pliny attributes tho discovery of glass to some merchants travelling with nitre, who, stopping on the bank of a river to take a meal, were at a loss for stones to reso their kettles upon. Putting them upon pieces of nitre, they kindled their fires ; the nitre, dissolved by the heat, mised witii the sand, and the merchants were sutonished to see a transparent matter flowing over the gronnd, which was nothing else but glass. Charles G-oodyear had for years experimented in vain, hoping to deprive iudia-rubber of its susceptibility to tho action of heat aud cold. Conversing with a friend on tho subject;, he emphasized an assertion by flinging a piece of sulphured rubber across the room. It lighted upon the stove ; and when he picked it up, a few days afterward, ho found the intense heat to which it had beeu subjected had conferred upon the india-rubber just the quality he liad so long stiiven to impart to it. Accordiug to some, he stumbled upon the discovery in a different manner ; but, at any rate, vulcanized indiurubber was the creation of un accident. A Dublin tobacconist, looking dolefully at his poor neighbours groping among tho smouldering ruins of his burnt-out shop, noticed that some of them, after trying the contents of certain canisters, carefully loaded their waistcoat pockets from them. He followed suit, and fouud th& snuif had come out of the fiery ordeal very much improved in pungency and aroma. Like a wide man he said nothing, but took another place, set up a lot of ovens, and before long Black Yard Snuff — otherwise, " Irish Blackguard " was all the rage with lovers of nasal titillation; and in a few years Luudyfoot was a rich man, owing to the accident he thought had ruined him. A would be alchemist, seeking to discover what mixture of earths would make the strongest crucibles* one day found he lud made porcelain. Instead ot transmuting; metals, as he hud fondly hoped to do, Bottner transmuted himself ; " as if he had been touched with a conjuror's wand, he was on u> sudden transformed from an alchemist iuto a potter." — * Chambers.' Journal.' ___^______ — _ __

A tax of fifteen dollars per quarter, which had been levied on Chinese laundrymen by the San Franciscans, has been declared unconstitutional.