Heating Source: Hearth

Alchemy usually involved a heating source, as it employed heat or fire as the basic transformational agent. In the early modern period, it was also called 'the art of the fire' or pyrotechnia (in Greek).  

A common heating source could be the hearth, now commonly known as a fireplace, a space in the interior of a building used to contain the fire for the purposes of heating or cooking. 

Converting such a hearth to alchemical uses involved raising its floor to the height of a table, to ease operation. The modified hearth (called an Esse) would often have a space underneath for storing vessels or instruments.

If the alchemical operations involved higher degrees of heat than usual, such as for molding or melting metals, a manual bellows was traditionally employed. This would 'stoke' the fire by blowing oxygen on it.  

The image above shows an Esse that  was further adapted for metallic operations. The bellows is incorporated into the hearth and is operated by a lever, thus mechanising the process further. 

Sources: Georgius Agricola, De re metallica (1556), p. 180. Ivo Purs and Vladimir Karpenko, The Alchemical Laboratory in Visual and Written Sources (Prague, 2023).