Gnomes are amazing creatures with a fascinating history. They were the first alchemists to ever exist, they let gems rest in water until it changed colours and absorbed the properties, they brewed teas and tested every material imaginable.
They kept track of their discoveries and shared it among them.
For a long time gnomes only lived underground, but the newer generations were unable to find new materials so they began moving above ground in search of new discoveries. They soon found human settlements and started trading potions for a place around the fire and a hot meal.
When humans built homes with gardens, they would build smaller homes in the garden that were perfect guest homes for travelling gnomes. In exchange, gnomes would leave potions for the humans as a thank you for their generosity.
Eventually, the habit of having a guest homes for travelling gnomes was as common a habit as making sure your home had a roof on it. Gnomes would then teach humans the secrets to alchemy, happy to share and knowing that humans would return the favour because humans were like gnomes in that sense, always ready to work together.