Pounds, Ampersands, and Skulls
Newton’s manuscript abbreviation “lb” (top left), an early printed # (top right), an italic & (bottom left), and the symbol for caput mortuum (bottom right). Images courtesy of the Roy G. Neville Historical Library, CHF.
August 31, 2010 | James Voelkel
Ever wonder why that # sign is called a “pound sign”? Or, for that matter, why the abbreviation for pound is “lb.”? An alchemical manuscript in Sir Isaac Newton’s handwriting provides part of the answer.
CHF is fortunate enough to hold a manuscript by one of alchemy's most famous practitioners, Sir Isaac Newton. A notation he made in the first line of the recipe brings to mind that weird denizen of the telephone key pad—the # or pound sign.
Newton wrote “take X lb. of,” but made the abbreviation in a very particular way. In one fluid line, he wrote the “l” and the “b” and then looped back around and drew a horizontal line through the tops of the letters. This style of abbreviation dates back to the manuscript tradition of the Middle Ages, when documents were written on expensive parchment made from animal skins and everything was methodically copied by hand. Scribes saved labor and resources by abbreviating heavily in a fairly standardized way.
The most common abbreviation was a line over a word or part of a word indicating the omission of letters. An “lb” with a line over it (or through it, since both letters have ascenders) was the abbreviation for “libra” or “librae,” the Latin word for “pound.” This abbreviation had been in use for centuries by the time Newton used it.
Early typefaces were able to reproduce a lot of the traditional manuscript abbreviations, but they fell out of use in time. One specialized symbol that survived was the pound sign cast as a single glyph. In early examples, it retained the loop on the “b,” but was later stylized with the loop of the “b” becoming the bottom crossbar of the #. Another familiar symbol sharing the same history is the ampersand—&—whose origins lie in the Latin “et” (“and”), as seen most often in italic typefaces.
One symbol that did not survive into our modern font sets was the chymists’ symbol for caput mortuum—literally “dead head”—meaning the residue left over after a chemical operation. In manuscripts, this was denoted with a small drawing of a human skull. Some 16th- and 17th-century publishers had the symbol in their type cases. It is charming, but uncommon to see.