Chemical Theater, or the Opened Door of Chemical Secrets (1693) - Page 28

furnaces, digestion furnaces original: digestif-ovens; used for gentle, prolonged heating, circulating furnaces original: circuleer-ovens; used for refluxing liquids so they boil and condense back into the same vessel, calcining furnaces original: calcineer-ovens; used to reduce substances to a powder or "calx" through high heat, melting furnaces, etc.

IV. The principal parts of a single furnace are the ash-hole, the hearth, the work-chamber original Latin: Ergastorium; the space within the furnace where the chemical reaction takes place, to which are added the mouths, grates, supports, vents, etc.

V. Fire is divided into four degrees according to its strong or weak heat, which one recognizes through sight, touch, and its effects.

VI. The first degree of fire is the gentlest of all, and is called digestive, circular, or putrefactive; it is the warmth of a bath at the beginning, which is equal to the warmth of horse manure original: paardemist; decaying manure was used in alchemy as a source of steady, low-level heat for fermentation, which the finger of the most delicate person can endure, also corresponding to freshly shed blood or fresh urine.

VII. The second degree can barely be endured by the hand, yet it is not harmed by it; it corresponds to warm water or the rays of the sun in the hot summer.

VIII. The third degree harms the hand and corresponds to boiling water or heated sand.

IX. The fourth degree is destructive and is called reverberating fire original: reverbereer-vuur; a high-intensity heat where the flames are reflected or "reverberated" onto the substance, which surrounds the material on all sides and consists of a bright flame; it corresponds to glowing iron filings.

X. Sometimes one also judges the degrees by the rapid or slow dripping of the drops [during distillation], measuring such by the beat of a person's pulse.

XI. There are still other distinctions of fire: that one fire is natural and the other is artificial; another closed, another open; another using a water-bath, or the dry vapor of sand, ashes, or steel filings; a bare reverberator, of...