The Venetians invented the income tax, statistical science, the floating of government stock, state censorship of books, anonymous denunciations (the Bocca del Leone), and the Ghetto. The idea of a Suez Canal was broached by Venice to the sultan in 1504. They were quick to hear of new inventions and discoveries and to grasp their practical application. When the news came to Venice, in 1498, of Vasco da Gama's voyage, rounding the Cape of Good Hope, the whole city instantly understood that it was bad news for their commerce: "the worst piece of information that we could ever have had." The telescope, which was invented in Holland in 1608, was known about in Venice before the end of the year. In 1610, it was being tried out from the Campanile, and a Venetian swindler was able to palm off a fraudulent one (made of plain glass) on the Grand Duke of Tuscany.
A Venetian doctor, Salamon, in 1649, anticipated biological warfare by concocting a plague-quintessence for use in the Turkish war. It was to be sown in the enemy's camps through the medium of cloth goods of the type the Turks liked to buy -- Albanian fez, for instance. "The proposition is a virtuous one," wrote the Venetian provveditore in Zara to the Inquisitors of State. "It is however... unusual and perhaps not admitted by public morality. But... in the case of the Turks, enemies by faith, treacherous by nature, who have always betrayed your excellencies, in my humble opinion the ordinary considerations have no weight." The Ten were interested in the proposition and, to make sure of a monopoly on the doctor and his jar of plague-quintessence, they put both of them in jail. In the event, as it seems, the invention may not have been used, possibly because the germs had gone stale -- a criticism leveled at the contents of the poison-cupboard in the Doge's Palace when it was checked in the eighteenth century. The Ten were always ready to listen to any ingenious person with a sure-fire scheme, to a murderer who offered to kill the king of Spain for 150 ducats, exclusive of traveling expenses, to a forger who guaranteed that he could forge in all languages....
The altane or roof terraces, now chiefly used for hanging out laundry, were a Venetian invention in the field of beauty. The Venetian ladies used to steep their hair in a chemical solution, and sit out on their altane, constructed for the purpose, in open-crowned hats, with the hair pulled through and spread out on the brim to bleach in the sun. Hence the golden tresses of Venetian painting. A little of that bleach seems to linger in the Venetian water-supply, for though the Venetians today are not, on the whole, blond, they are not brunette either, but dark with blond highlights. They have kept the fair skin too that the wide-brimmed hat shielded.
The Venetians first developed the glass mirror commercially in the Murano glass works. They held a monopoly of the art for over a century during the Renaissance. Any mirrormaker who took his art into a foreign state could have his nearest relations imprisoned, and Venetian agents were commissioned to kill him on sight. As late as the seventeenth century, Colbert, Louis XIV's minister, used poison and women to keep certain Venetian mirror-makers in France, and on his death a Venetian mirror, measuring 42 by 26 inches, was found among his effects and inventoried at nearly three times the price of a Raphael.