A Brighton stationer took a fancy for dressing his show-window with piles of writing paper, rising gradually from the largest to the smallest size in use; and to finish his pyramids off nicely, he cut cards to bring them to a point. Taking these cards for diminutive note paper, lady customers were continually wanting some of "that lovely little paper," and the stationer found it advantageous to cut paper to the desired pattern. As there was no space for addressing the notelets after they were folded, he, after much thought, invented the envelope, which he cut by the aid of metal plates made for the purpose. The sale increased so rapidly that he was unable to produce the envelopes fast enough, so he commissioned a dozen houses to make them for him, and thus set going an important branch of the manufacturing stationery trade. _Etching upon Glass._ This process was discovered by accident about the year 1670, by an artist named Schwanhard. We are told that some aqua-fortis having fallen by accident upon his spectacles, the glass was corroded by it. He thence learned to make a liquid by which he could etch writing and figures upon glass. _Lundyfoot's Luck._ The shop of a Dublin tobacconist by the name of Lundyfoot was destroyed by fire. While he was gazing dolefully into the smouldering ruins, he noticed that his poorer neighbors were gathering the snuff from the canisters. He tested the snuff for himself, and discovered that the fire had largely improved its pungency and aroma. It was a hint worth profiting by. He secured another shop, built a lot of ovens, subjected the snuff to a heating process, gave the brand a particular name, and in a few years became rich through an accident which he at first thought had completely ruined him. _Citric Acid._ A London chemist was the inventor of citric acid, and, having his own prices as long as the way of making the acid was a secret, realized a large fortune. This chemist trusted nobody, but worked entirely alone. He thought his secret very safe. It was necessary, however, to have a chimney to his laboratory, and chimneys sometimes want sweeping. A rival, disguising himself as a chimney-sweep, got into the sanctum. He had all his eyes about him, as the saying is, and, when the chimney was swept, knew how to make citric acid, and thus a monopoly was ended. _A Half-Starved Tramp._ Mr. Huntsman, who had devised some important processes in the manufacture of cast steel, built his factory, to be out of observation, in the middle of a bleak moor, and "No Admission for Strangers" was painted on the outer gate. One terribly snowy night, however, a poor, belated, half-frozen traveler, who said he had lost his way on the moor, craved shelter, was charitably admitted, and was placed near the furnace, to be thawed. He watched what was done, and, being an expert, took it all away in his mind. Next morning he walked away, and took the secret with him. So perished Huntsman's El Dorado.