Has the word 'focus' ever meant 'fire' in Latin literature?

The Latin word focus meant “hearth, fireplace.” In the scientific Latin of the 17th century, the word is used to refer to the point at which rays of light refracted by a lens converge.

1. Which comes from a Latin word meaning fire?
2. What is the origin of the word focus?
3. Does Vulgar Latin exist?
4. When did Vulgar Latin start?

Which comes from a Latin word meaning fire?

The latin word 'Ignis' means fire. Igneous rocks are formed through the cooling and solidification of magma and they get their name from the Latin word for fire.

What is the origin of the word focus?

Well, the word focus comes directly from the Latin focus, which meant “fireplace” or “hearth” (that is, the floor of a fireplace). This is what focus originally meant in English when the word entered the language around 1635–45, though that sense has been extinguished, as it were.

Does Vulgar Latin exist?

Vulgar Latin, also known as Popular or Colloquial Latin, is the range of non-formal registers of Latin spoken from the Late Roman Republic onward. Through time, Vulgar Latin evolved into numerous Romance languages.

When did Vulgar Latin start?

The form of Vulgar Latin that is considered in Wiktionary's entries is primarily the latest common ancestor of the Romance languages, spoken during the later days of the Roman Empire, the 2nd to 4th centuries. This time is more or less concomitant with the Late Latin period of classical Latin.