Diana's Tree

Alchemy is a category of science that makes assumptions about nature and involves the use of minerals, metals, and the synthesis of medications.[5] Although now considered a pseudoscience, the practice of alchemy has contributed experimental techniques to the chemistry world such as the process of distillation and sublimation.[5] Alchemy was an early version of chemistry combined with metal work; one of the main goals of early alchemists was to create what was known as the Philosopher’s Stone, a substance that when heated and combined with a non precious metal like copper or iron (known as the “base”) would turn into gold. The Tree of Diana was a precursor to the Philosopher's stone: experiments involving the Tree aimed to turn non precious metals into precious metals like gold or silver, similar to the Philosopher's stone. Alchemy began as a quest for knowledge and to understand the world, but the practice did not make it far past the Enlightenment (around 17th and 18th centuries). However, many serious chemists throughout history were also alchemists, including Isaac Newton.[6]

In pre-modern chemistry, the various methods for procuring Diana's Tree were exceedingly time-consuming; for example, the following process, originally described by Nicolas Lemery, required forty days to see results:

"Dissolve an ounce of pure silver in a sufficient quantity of aqua fortis, exceedingly pure, and of a moderate strength, and having put the solution in a jar, dilute it with about twenty ounces of distilled water. Then add two ounces of mercury, and leave the whole at rest. In the course of forty days, there will rise from the mercury a kind of tree, which throwing out branches will represent natural vegetation."[7]

Giambattista della Porta in the 16th century described it this way:

"Dissolve Silver in Aquafortis, evaporate into thin air at the fire, that there may remain at the bottom a thick unctious substance. Then Distill fountain water twice or thrice, and pour it on the thick matter, shaking it well. Then let it stand a little, and pour into another glass vessel the most pure water, in which the Silver is. Add to the water a pound of Quicksilver, in a most transparent crystalline glass that will attract to it that Silver. And in the space of a day there will spring up a most beautiful tree from the bottom, and hairy, as made of most fine beards of Corn, and it will fill the whole vessel, that the eye can behold nothing more pleasant. The same is made of Gold with Aquaregia."[8]

17th century American alchemist George Starkey, who wrote under the pen name “Eireanus Philalethes,” had a recipe for sophick mercury that produced a branch-like structure consisting of an alloy of gold and mercury. His process involved the repeated distillation of the mercury, which he then heated while adding gold to produce the structure. Historian of science Lawrence Principe has reconstructed and recreated recipes for Diana's tree used in the 17th century. In one version, he used a small seed of gold mixed with mercury to create the “Philosopher’s Tree.” Principe explained that the creation of gold from gold itself was obviously possible.[9]

A recently discovered manuscript by Isaac Newton shows a recipe that Newton copied from a text by Starkey that vaguely explains how to make “sophick mercury,” a substance that was thought to be the main ingredient of the Philosopher’s Stone. While there is no evidence that Newton made his own version of Diana’s Tree, one of his old manuscripts did have a recipe for Diana’s Tree, along with Newton’s own notes, that was copied from a text by alchemist George Starkey.[10] In the same manuscript are notes written by Newton that explain his own procedure for alchemically subliming lead ore, a process that occupied many of his laboratory efforts to create the Philosopher’s Stone. Isaac Newton kept his experiments on alchemy a secret, as the practice was illegal in England at the time. In addition, much of Newton's work regarding alchemy was lost in a fire supposedly started by his dog.[11]

The quickest method, as described by German natural philosopher Wilhelm Homberg (1652-1715), took about a quarter of an hour, and is described as follows. Take four drams of filings of fine silver, with which make an amalgam, without heat, with two drams of quicksilver. Dissolve this amalgam in four ounces of aqua fortis, and pour the solution into three gallons of water. Stir it for a while until mixed, and then keep it in a glass vessel well stopped. To initiate the experiment, take about an ounce of the substance, and put it in a small vial; add to this a quantity the size of a pea of the ordinary amalgam of gold, or silver, which should be as soft as butter. Let the vial rest for two or three minutes. Immediately after this, several small filaments will visibly arise perpendicularly from the little bulb of the amalgam, which will grow and thrust out small branches in the form of a tree. The ball of amalgam will grow hard, like a pellet of white earth, and the little tree will be bright silver in color.[12]

The form of this metallic tree may be varied as desired. The stronger the user makes the first described water, the thicker the tree will be with branches, and sooner formed. Homberg also described how numerous other kinds of trees may be produced by crystallization and "digestion".[12]

There is also Saturn's Tree, which was a deposit of crystallized lead, massed together in the form of a "tree". It is produced by a shaving of zinc in a solution of the lead(II) acetate. In alchemy, "Saturn" was the name used for lead.[2]

Sophick mercury: a combination of distilled mercury, gold, and heat

Over time, the Tree of Diana has been recreated using various processes and ingredients. One of the earliest recorded recipes of the “tree” involves the continuous distillation of mercury and then heating it with gold. An alloy metal would be created, and its branch-like formations looked similar to the Tree of Diana. The sophick mercury experiment is said to have potentially influenced Isaac Newton in later experiments, and it is believed that he used lead instead of mercury in his own tree creations. While the timeline for recipes is slightly blurred, various recipes in the past show that many alchemists were attempting to make a tree. The sophick mercury formation of the tree was a stepping stone for other tree formations and experimentations involving the mixture of metals in the future.[13]

Modern versions using copper

The formation of these “trees” using different metals has fascinated chemists for hundreds of years. Experiments with the Tree of Diana have inspired modern experiments that analyze the reaction between a metal and other substances. One recent experiment at the University of Seattle, Washington examined the reaction between solid copper and aqueous silver nitrate. Silver ions react with the copper metal to form a crystal structure, and this reaction proceeds until the concentration of silver ions is exhausted. The set-up of this experiment is very similar to the format of the experiments that were conducted to create the Tree of Diana in the past. This experiment was inspired by the work of early alchemists that attempted to produce the Tree of Diana. Early alchemists attempted to “grow” a precious metal like silver or gold with the reaction of these precious metals and another substance, creating the tree-like structure.[14]

• "Arbor Dianæ" . New International Encyclopedia. 1905.