Terra fluida

In 1667, Johann Becher (1635-1681), a chemist interested in the origins of metals, published Physicae subterraneae. He argued that there were three earths terra fluida (mercurious earth), terra lapidea (vitreous earth), and terra pinguis (fatty earth). It was terra pinguis that produced combustible... 

In his 1664 Oedipus chimicus (see Figure 162). Becher describes his early concepts of the elementary composition of matter. His most famous work is his 1669 book commonly referred to as the Physica subterranead ° In this work, Becher argued that air, water, and earth constituted the true elements with air being an instrument of mixing. Metals and stones were said by Becher to be composed of three earths terra vitrescible (glassy earth—the substance of subterranean matter), terra pinguis (fatty earth—combustibility) and terra fluida (odor, volatility, and other subtle properties). Becher concluded that all substances that... 

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