In the summer of 1818 Stendhal took a recreational trip to the salt mines of Hallein near Salzburg with his friend and associate Madame Gherardi. Here they discovered the phenomenon of salt “crystallization” and used it as a metaphor for human relationships.
"In the salt mines, nearing the end of the winter season, the miners will throw a leafless wintry bough into one of the abandoned workings. Two or three months later, through the effects of the waters saturated with salt which soak the bough and then let it dry as they recede, the miners find it covered with a shining deposit of crystals. The tiniest twigs no bigger than a tom-tit’s claw are encrusted with an infinity of little crystals scintillating and dazzling. The original little bough is no longer recognizable; it has become a child’s plaything very pretty to see. When the sun is shining and the air is perfectly dry the miners of Hallein seize the opportunity of offering these diamond-studded boughs to travellers preparing to go down to the mine."