Terra pinguis

In 1667 Becher published another book, Physica Subterranea, in which he expounded a theory that was to profoundly affect chemistry for more than a century. In the book Becher accepted only two of the traditional four elements, earth and water. He then divided earth into three types, so that in effect there were still four elements. He named the three kinds of earth terra lapida, terra pinguis, and terra mercurialis. The second of these, which he described as an oily earth, was supposed to be present in all combustible substances and was released when those substances burned. 

To some chemists phlogiston was fire itself a form of the ancient element. Others, accepting the blurring of the demarcation between elements and alchemical principles , concurred with Becher s definition of terra pinguis-. Metals contain an inflammable principle which by the action of fire goes off into the air. ... 

It is difficult to see in the characteristics and properties of the three earths of Becher any substantial improvement on the tria prima of Paracelsus and his successors, other than the avoidance of the use of the three names which were in common use in two different meanings. For the three principles of that name, as chemists of that school took great pains constantly to explain, were not the same as the common substances so named. Nevertheless, the new name terra pinguis or fatty earth for the older sulphur, as the substance which departs in combustion, certainly gave the stimulus which incited Stahl and his followers to develop the influential phlogistic hypothesis and Becher thus played a not unimportant part in the history of chemical theory. 

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... 

Becher (1635-82), tried to rationalize this notion further, by introducing a new name. He imagined solids to be composed of three kinds of earth. One of these he called terra pinguis ( fatty earth ), and felt this to be the principle of inflammability. 

It had long been regarded as self-evident that combustion represented the decomposition of a material into simpler substances. In 1669 Becher combined this idea with his suggestion that all bodies were composed of air, water and three earths, which he called terra pinguis, terra mercurialis and terra lapidea (fatty earth, mercurial earth and stony earth). Becher proposed that terra pinguis escaped when combustion occurred. 

Although the 17 Century was a time of notable scientific progress, the scientists of the day were themselves far less respected and far less listened to than today s scientists. Some of them, such as Newton and Leibniz who are responsible for the introduction of many modem theories, were also devoted alchemists. The idea of " fire fluiglobular particles that attach easily only to combustible objects) persisted for another two hundred years and assumed that when a substance is burnt, the non-substantial essence ( terra pinguis ) escapes. The definition of the laws of conservation needed more precision on account of the action of traditional vital and mortal forces. Conservation was assumed to be something general between and within the system as probably first noted by the non-cited Czech educator Marcus Marci [121 ]. 

Stahl Georg Ernst (1660-1734) Ger. chem., renamed Becher s terra pinguis as phlogiston, observed acids have different... 

Fig. 6.1 J. J. Becher (1635-1682) thought matter to be composed of terra lapida (stone the principle of solids), terra mercurialis (mercury the principle of weight and lustre), and terra pinguis (fat, oil the principle of combustibility). When heated in air (calcination) metals lose terra pinguis and form kalx (chalk, from the Greek word for ash)...

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