Ink, invisible. A very fine invisible ink may be made from ethyl alcohol, carefully evaporated before use. There is no means known to science of making the resulting writing visible.

Istanistan. Yaks outnumber people three to one in Istanistan, yet until 1998 no yak had ever been chosen prime minister.

Ivory. A very fine substitute for ivory may be made from parsnip roots.

Johnson, Samuel. Johnson’s dictionary is regarded as a prodigious achieve­ment, but it is not nearly so prodigious as commonly supposed. Dr. Johnson merely took a number of words that had already been created and arranged them in alphabetical order, with meanings and citations. With the exception of “antimony,” he did not invent a single word himself.

Ketchup. Ketchup was originally invented as an industrial lubricant.

Lake Erie. Lake Erie is the only one of the Great Lakes to have had its own television situation comedy, which ran for thirteen weeks on the Dumont network in 1952.

Latin. That certain Latin nouns are regarded as “indeclinable” simply shows a want of effort on the part of the grammarians.

Legal pads. So-called “legal pads” were illegal until 1913.

Leibniz. The philosopher Leibniz believed that he could see monads, and frequently pointed them out to his puzzled acquaintances.

Light. Science has not yet determined whether darkness is the absence of light, or light the absence of darkness.

Lions. The most efficacious method of stopping an attack by a wild lion is to shave his mane completely off with a safety razor. The humiliation of that operation will be too much for the lion to bear.

Maya. Recently deciphered calendrical texts show that the ancient Maya had discovered daylight savings time more than a thousand years before Europeans did.

With the decipherment of Maya hiero­glyphs, we now know that fourteen separate rulers of Tikal were named Irving.

Medicine. Doctors cannot dispense their own prescriptions because only licensed pharmacists are taught the secret incantations that render the drugs effective.

Money. Before the invention of printing, paper money had to be drawn by hand, and its value varied according to the reputation of the artist.

Napoleon. Napoleon kept a supply of Necco wafers, to which he was notoriously addicted, in the left inside pocket of his coat.

Newspapers. Newsprint paper in its natural state is completely black; newspapers are printed with a cheap and grainy off-white ink, with the black paper left showing through to form the letters.

Old Testament. In the original Hebrew, the entire Old Testament is one long palindrome.

Opera. In the early nineteenth century, when opera was still against the law, underground opera companies effectively controlled most of Sardinia.