This expression is frequently used after a nap or a bad night, to say that one is not awake or still half asleep… but its origin is far from sleep.
In the landscape of French expressions, some have a very telling image. This is the case of the expression “to be in the coaltar”. Now part of everyday language (although a little outdated), we use it in the event of a difficult awakening, when we cannot emerge, after a nap that is a little too long, a sleepless night or quite simply to describe a feeling of mental fog. If the meaning is clear to everyone, its origin is often not known.
First thing to admit: few people know the spelling of the word “coaltar”. For good reason, this word is not French but English. It is the combination of the two words: “coal” which means “coal” and “tar” (found in “tarmac”) which means “tar”. Coal and tar, what connection with sleep? Originally, coaltar is a viscous, black and sticky liquid resulting from the distillation of coal. In the 19th century and the beginning of the 20th century, it was widely used to protect the hulls of boats, waterproof roads or even to treat telegraph poles, explains the Historical Dictionary of the French Language (Alain Rey/Le Robert).
The expression “being in the coaltar” was thus built on a very simple physical metaphor. To be “in the coaltar” is symbolically to have the impression of swimming in a thick and sticky substance which slows down all movements and disrupts thoughts. As this product is a deep black, the idea of “not seeing anything” or having foggy ideas naturally emerged.
Finally, the tar vapors are strong, acrid and heady. Breathing these scents on construction sites or ports often caused dizziness and nausea, plunging individuals into a daze, close to drunkenness or daze. It’s quite ironic: while the word coaltar comes directly from English, English speakers absolutely do not use the expression “to be in the coaltar” to talk about their fatigue! To translate this feeling of mental fog or difficult awakening, they use the expression “to be in a fog” or “to be groggy”.
Although the chemical has now largely disappeared from our lives, the image remains extremely effective. It joins other expressions such as “being in the pâté”, “being in the polish” or “having your head in the gas” and illustrates this fascinating capacity of the French language to transform industrial residues into nuances of the soul and the body. So, when we emerge painfully from a too-short night, we unknowingly carry the legacy of the sailors and workers of the last century, stuck in coal.
