We now proceed to the more compound genera.

Salts with Earths and Inflammables.

§ 257.

This genus can hardly ever occur but in countries formerly expoſed to ſubterranean fires.[[77]]

Salts with Earths and Metals.

§ 258.

To be expected amongſt volcanic productions.

Salts with Inflammables and Metals.

§259.

To be ſought for in the productions of volcanoes.