Life: A User's Manual (The Good Parts)

3 - Unica

(p 82)

In the jargon of the rare book, antique, and curio trade, a unicum, as its name implies, is an object which is the only one of its kind. 

This rather vague definition covers several classes of object; 

it can mean things of which only one example was ever made, such as the octobass, a monstrous double-bass for two musicians, one at the top of a ladder doing the fingering, the other on a mere stool drawing the bow, or the Legouix-Vavassor Alsatia, which won the Amsterdam Grand Prix in 1913 but was never marketed owing to the war; 

or it can mean animal species of which only one member is known to exist, like the tendrac Dasogale fontoynanti, the sole specimen of which was caught in Madagascar and is now in the Natural History Museum in Paris, like the butterfly Troides allotttei bought by a collector in 1966 for 1,500,000 francs, 

or like the Monachus tropicalis, the white-backed seal whose existence is known only by a photograph taken in 1962, in Yucatan; 

or it can mean objects of which only one example now remains, as is the case for several postage stamps, books, engravings, and sound-recordings; 

or, finally, it can mean objects rendered unique by this or that detail of their history: 

the pen with which the Treaty of Versailles was initiated and signed, 

the breadbasket into which the head of Louis XVI or Danton rolled, 

the stub of the piece of chalk Einstein used at his memorable 1905 lecture, 

the first milligram of pure radium isolated by the Curies in 1898, 

the Ems Telegram, 

the boxing gloves Dempsey wore to defeat Carpentier on 21 July 1921, 

Tarzan's first underpants, 

Rita Hayworth's glove in Gilda, 

are all classic instances of this last category of unica, the most common but also the most slippery class, when you think that any object whatsoever can always be identified uniquely and that in Japan there is a factory mass-producing Napoleon's hat, or Napoleon hats.