In the history of light, a wide range of light sources has been used. In the 19th century for instance, candles were used made out of spermaceti oil, a wax-like substance found in whales. Each whale had around 4 tons of this substance in its head. Candles made out of this whale oil, were at that time the best quality candles with a bright and scentless flame. This wonder ingredient led to an intensified hunt for whales between 1835 & 1875, leading to approx 300.000 caught whales. Luckily new innovations in light stopped the intensive whale hunt, avoiding its extinction.