Sep 08 2026

Book review: The Secrets of Alchemy by Lawrence M. Principe

My next review is of The Secrets of Alchemy by Lawrence M. Principe, this was recommended reading from Alchemy by Philip Ball.

The book consists of seven chapters, the first five of these are chronological covering the Greco-Egyptian origins of alchemy, developments in the Islamic world, and the medieval period; at this point the chronology breaks to cover the 18th century onwards which involves the reinterpretation of alchemy before returning to the Golden Age of alchemy in the Early Modern Period (1500AD-1700AD).

The final chapters are on interpreting alchemical texts, and alchemy in wider society.

My aim in this review is not to repeat comments on the history of alchemy that I made in my review of Philip Ball’s book but rather to highlight what felt new in this book.

The small disorder in the chronology is to highlight how our modern view of alchemy is to a large degree influenced by the 18th century where “scientists” were carefully splitting respectable chemistry from not so respectable alchemy. The “not so respectable” part of alchemy has always been chrysopoeia – making gold from base metals – it has been the symbol of alchemist wasting their life, and frittering away their money on a fruitless enterprise or it has been seen as fraud.

The Victorians adopted alchemy as part of the spiritualist revival adding more mystical elements to it. This coloured the views of early historians of science who tended to write off the whole subject in terms of scientific content.

What excited me about this book early on is that the author went to the trouble of repeating some alchemical recipes in the modern laboratory. In one example he discovers that a reaction doesn’t work as described when a pure starting material is used but does work when the natural ore from the place where the alchemist in question worked because of the presence of silicon dioxide in the ore. In another he discovers that a described reaction works if an iron rod is used to stir the mixture, as specified in the recipe but the products observed are actually compounds of iron rather those that the alchemist believed they had made. This reflects modern laboratory practice; method descriptions that are pretty good but sometimes overlook the impact of apparently minor details and it isn’t unknown for modern scientists to make products different from those they were attempting to make!

These recreations highlight that alchemists could be very sophisticated experimenters not only in terms of the equipment they used but also, for example, observing changes in weight during chemical reactions.

Alchemical experiments were motivated by ideas about how substances are constructed which go back to the earliest writer in alchemy; in 300AD Zosimos of Panopolis was writing about theoretical principles and making observations. He talks about all metals containing a body (which makes them metals) and a spirit which gives them particular properties. Therefore the task of transmutation is to extract the “spirit” of a base metal and replace it with the “spirit” of gold. Later the Arabic writer Jābir ibn Ḥayyān talked in terms of a Mercury-Sulphur theory which evolved into something more elaborate linking with the the Aristotelian classical elements and Galen’s humors. We would now consider these theories utterly wrong but they are the same shape as our modern theories. These types of theories maintained until the late 18th century when our modern ideas of chemical elements were developed.

We also see a leakage of language from alchemy into modern day chemical terms, for example, the Greek God Hermes was long associated with alchemy and glass vessels were closed with “the seal of Hermes” which becomes “hermetically sealed” in modern parlance.

As I commented in my review of Ball’s book, alchemy seems to have been particularly rife with publishing under other people’s names. The Jabirian corpus is one example of this. A couple of items to add to this, Principe comments at one point in this book that in some cases transcriptions of ancient documents mix in works from other authors. For example, ibn-Sina’s text on mineralogy was attached to a translation of Aristotle’s Meteor giving ibn-Sina’s work more gravitas. Secondly, alchemy developed a culture of dispersing information across many small “publications” with initiates into the culture expected to read widely across the corpus to find out what to do rather than find everything in one place.

Obfuscation is a key theme in much writing on alchemy. The mindset was of special knowledge which was available only to initiates in the culture. Understanding alchemical documents was not a simple act of reading, it required wider understanding. The use of Decknamen (aliases used to describe reagents in alchemical recipes) is a recurring theme in the book – these can change through the course of a document.

The case of George Starkey (1628–1665) is particularly revealing because in his case we have his works under a pseudonym (Eirenaeus Philalethes) but also at least some of his laboratory notebooks. We can see an obfuscated alchemical recipe in one of his books alongside the same recipe in plain language in a letter sent to Robert Boyle.

The Early Modern Period encompassed more varied publishing formats, for example each chapter in Michael Maier’s 1617 Atalanta fugiens featured a motto, an emblematic image, a six-line epigram, 2 pages of prose and a piece of music! This is reminiscent of Erasmus Darwin’s epic poems about botany from the late 18th century.

Emblematic images are a recurring theme in the book, they illustrate an alchemical process using allegorical symbols rather than literal illustrations of the process. Principe warns us we need to see them in the context of the text in which they are found – the emblematic image re-iterates the text. So, for example, in Basil Valentine’s 1602 book Von dem grossen Stein der Uhrhalten the text about purifying gold says “take the ravenous grey wolf that on account of his name is subjected to bellicose Mars but by birth is is a child of old Saturn” means to take the antimony ore stibnite to purify gold. Each metal had an associated planet, and Saturn is the planet associated with lead but we are looking for a child of Saturn which is stibnite (an ore of antimony) which at the time was seen as related to lead. The allegory is reinforced because molten stibnite will dissolve gold very quickly – it is “ravenous”. It has the air of a cryptic crossword clue and I would imagine these texts would be relatively easy to read for those in the know.

The final chapter talks about alchemy in wider culture, it appeared in plays and even Shakespearian sonnets. There was also a long standing interplay with religion – the theme of purification appealed both to alchemists and preachers.

I think this may become one of my favourite books of the year, Neurotribes by Steve Silberman is the only one I might rank above it.

Aug 17 2026

Book review: Symbols and Allegories in Art by Matilde Battistini

My next review is of Symbols and Allegories in Art by Matilde Battistini which I discovered is part of a series: Guide to Imagery which looks interesting. I found this book by searching because I was interested in understanding more about allegories in art. I knew from watching various TV programmes that there was more to paintings than their surface appearance.

Symbols is divided into an introduction, and four sections on Time, Man, Space and Allegories, each of which describe twenty or so items. Each entry describes the linguistic and mythological origins of a term and is illustrated with at least one painting or sculpture with parts of the artwork labelled. Sometimes subsequent pages show more related artworks with labels.

Most of the paintings are from the Medieval and Renaissance periods but there are some artworks from the 19th and even 20th century. I think they are all from Western Europe presumably the allegorical language elsewhere is different.

Allegorical content in artworks evolved over time, in the Medieval period it was very much about good and evil, focussed around the Christian faith. Much of the iconography of early Christian art was based on earlier mythology. During the Renaissance there was a greater direct focus on Classical themes and mythology. Later the use of allegories was codified into documents – it was a pity not to see references to an example of this. Within Christian iconography there is an evolution from the Medieval period.

I think this book is intended for the somewhat expert in art history, it doesn’t talk about why allegories appeared in paintings and who made art for whom.

In many cases the paintings helpfully contain the word “allegory” in the title, so the reading is not as blind as you might think.

Since there are a limited number of sections each section is quite broad, so the section on time includes seasons, months, times of the day, ages of man and the world and items representing the flow and circle of time.

The Seasons appear early in the book and are a good illustration of how sets of things are represented allegorically. The seasons are associated with different phases of human life birth (spring), maturity (summer), decline (autumn) and death (winter). They are also associated with animals (ram, lion, bull and snake) and gods (Zeus, Helios, Dionysus, and Hades) in Greek mythology. Seasons can also be represented by women, we can identify which season by their headwear – Spring is represented by a woman with a crown of flowers, Summer with a crown of wheat stalks. More widely figures are recognised by the objects they hold or are close to, Saturn for example is shown as an older man carrying a scythe or hourglass.

The section on man contains entries on key biblical figures like Christ, the Virgin Mary, Eve, the Trinity, angels and Satan. As well as a range of monsters of different types. There are also what seem like miscellaneous entries on eggs and mirrors. The idea of the Trinity was created in 325AD at the Council of Nicea; angels only gained wings in art in the 4th century AD and that the iconography of the Virgin Mary derives from earlier gods such as Artemis and Isis. I was interested to learn that haloes come from Indo-Iranian deities via Roman and Byzantine emperors before reaching Christianity.

One of the pictures for the Monsters entry is Piero di Cosimo’s, Perseus Frees Andromeda which features members of the Medici family – a hidden meaning not otherwise covered in the book.

The section on space covers the astronomical (sun, sky, cosmos, moon), the earthly (garden, mountain, forest, tree) and the religious (Heaven, Hell, Purgatory, Limbo). Dante’s Divine Comedy, completed in 1321, is cited a few times as a source for depictions of Hell, Purgatory and Limbo. The representations of Hell stabilised in this period.

The final section on “Allegories” is a bit different from the others, it covers items like The Senses, The Virtues, The Vices but there are rather fewer items than in the earlier sections but each is illustrated by more examples. Love is included in this section where we learn the parrot is a symbol of lust! Young women represent the cardinal virtues: fortitude, prudence, justice and temperance and the theological virtues: faith, hope and charity. The cardinal virtues derive from ancient Greek philosophy whilst the theological ones are medieval.

I must admit this book got me thinking about data. Is there a global database of paintings? How often does “allegory” appear in the title? And the somewhat off-topic question of what fraction of the paintings made in any particular period / place survive?

I found this book interesting and readable although I was expecting more on the framework into which allegorical depictions lay. The parent series definitely seems worth a look.

Jul 30 2026

Book review: A History of Railways in 100 Maps by Jeremy Black

Bookshops are dangerous places, I visited one and came away with A History of Railways in 100 Maps by Jeremy Black! It is a book my dad would have loved.

A History of Railways is approximately A4 format, as well as an introduction it contains eight chapters. The first six of these are chronological and named: Origins, Spreading the New Age (1860-85), Geopolitics and War (1885-1918), Alongside Road (1919-39), War and Air Challenge (1939-70), and Rail Developments (1970-present). It finishes with chapters on “Facing the Future” and “Rail and the Collective Imagination”. Each chapter contains a series of maps, typically they are shown with a facing page of text, occasionally there are two maps associated with a piece of text.

The style of presentation, as a hundred individual maps, makes it a little difficult to pull together themes, although the chapter introductions help with this. Britain features repeatedly but the coverage is global, and Britain’s representation is just a result of the early start made on railways in the country.

The format of maps evolved over the years, as technology improved. Surveying, mapping and printing had developed through the 18th century, prior to the railways, in part to support the creation of turnpike roads and then canals as well as prospecting for minerals for the developing Industrial Revolution. A recurring theme is that the maps rarely present terrain, simply connectivity. Early maps made to promote new lines often featured indications as to what resources (mineral or agricultural) were produced in the areas through which the railway passed. Occasionally there were innovations in presentation, such as using line width to encode freight volumes. In the 20th century novel pictorial formats appeared – advertising for leisurely rail travel.

In Britain railways were not centrally planned but there was oversight via parliamentary act – other countries went for centrally planned systems. Initially many railways were designed to link the production of materials with ports. Railways powered the Industrial Revolution, enabling heavy raw materials to be transported at low cost, and the timely distribution of goods produced. Railways drove the expansion of cities allowing goods, raw materials and people to be brought in daily over significant distances. In Britain rail freight increased more than 10-fold between1850 and 1912. Night travel become more important with signalling improvements.

As the railways grew globally Britain was central in terms of technical know how but also in terms of financing. In different countries the rise of the railways was driven by different commodities – in Uruguay it was beef, in Chile nitrate fertiliser and again linking material production to ports was central.

Prior to the rise of air travel and to a lesser extent car travel, the railways were also associated with luxury enabling pastimes like skiing. I was surprised to learn that the Orient Express service was a locomotive with just three carriages.

In most countries there was a diversity of competing rail companies as the railway systems grew. During the early 20th century there was a tendency for these to merge, many turning out to be uneconomic despite the promises of their developers. This accelerated later in the century as railways declined due to competition from road and air travel.

War features in two chapters, the railways have been central to war for a long time – for troop mobilisation and also to move supplies. During the American Civil War the Union rail network was far more developed than that of the Confederacy which helped them to victory. They are critical even now in Ukraine, for example. In addition to existing railway infrastructure specialised railways were built to support fighting in the trenches during the First World War.

Railways suffered in the post-war periods, typically they had been degraded by attacks and lack of investment during war and then after the war investment was hard to come by. In Britain the 1926 General Strike took a lot of freight off the railways, never to return. Road offers access at all points on a road for low or zero cost. Road vehicles were much cheaper and required limited training. After the Second World War air travel started to take passengers from rail, particularly in Australia, the US and Canada.

In response railways switched to diesel and electric drive reducing costs somewhat but there were widespread managed decline projects such as that of Beeching in the UK. I was surprised to learn that, despite this, American rail freight is quite successful and where they exist passenger services are not doing badly.

There are still grand new rail projects under way such as in Spain, for example, where a high speed rail system is seen as a counter to regional separatist movements. In Asia China’s belt and rail projects are looking to span the continent (despite shipping freight being cheaper). There is a project linking the Baltic states whose existing rail systems focussed on Moscow rather than each other. Delhi is expanding its suburban rail system. In the England HS2 is much reduced largely because it is costing £85 million per kilometre rather than the £13 million per kilometre typical in continental Europe a disparity arising from the large number of tunnels and viaducts built to mitigate local opposition. The COVID pandemic has also led to a 10% reduction in passenger traffic in the UK changing the economics of new railways.

The final chapter of A History of Railways is on various fictional maps and games based on the railways including a map of Sodor, Thomas the Tank Engine’s home island.

This is a beautiful book, the scope is very wide and thus a bit shallow but it provides an interesting overview of the history of railways through vignettes rather than a sweeping narrative.

Jun 30 2026

Book review: This way up by Mark Cooper-Jones and Jay Foreman

My next review is of This way up: when maps go wrong and why it matters by Mark Cooper-Jones and Jay Foreman – a book about maps with something wrong with them, sometimes the errors are accidental but others are deliberate. It is based on the authors’ YouTube channel – Map Men – which has a rather broader scope.

The style of the book is very relaxed but varies from chapter to chapter, one is a podcast transcript, whilst another is a series of fictional letters. One chapter is one sentence long, asking whether a globe is a map (it isn’t).

The chapters are pretty much entirely independent of one another, although the authors note that Google Maps is a little bit of a recurring theme.

This Way Up sometimes talks about when maps are just wrong, for example IKEAs world map which omitted New Zealand, this mistake is sufficiently common that there’s a MapsWithoutNZ reddit. Related to this are erroneous maps on the TV. Both of these arise from the technical process of getting maps into production.

All maps are likely “wrong” because they contain fake places known as copyright traps to catch out people copying them – the chapter on this involves the fictional town of Aglow in the Catskill mountains which has been cited as a copyright trap but mysteriously became a real place – perhaps so that a copier could avoid a copyright challenge!

Some maps are “wrong” for political reasons, in disputed territories such as Kashmir or Taiwan. The UK has a relatively benign version of this, it is now illegal for public bodies to put Shetland in a box in public maps. I struggled with this chapter because it was written as a poem!

In the Soviet Union maps were routinely censored or rendered inaccurate for reasons of secrecy, an exercise in futility once satellite imagery became routinely available.

There are a couple of maps on the birth and growth of the United States, one illustrates it is ill-advised to base borders on vaguely known geography. The northern border with Canada in the west was based on the north west extremity of the Lake of the Woods – a rather intricate body of water, and a projection west to the Mississippi River which it turned out didn’t go so far north. The second map relates to the Donner Party, a group of American settlers heading out to California whose voyage ended in cannibalism. They had left Independence in Missouri rather late in the season which meant they risked being caught by snow in the Sierra Nevada mountains. As a result of this time pressure, they elected to take the “Hastings Cutoff”, a route promoted with a map – inaccurately as it turned out – which would have saved them time.

The “Mountains of Kong” appeared on maps of West Africa following James Rennell’s 1798 map, they persisted through the 19th century and have actually appeared on a map published in 1995. They don’t actually exist, which has been known since about 1890. Rennell had added them to his map on the basis of very limited information and with a desire not to leave blank spaces, his maps were used as the basis of further maps since original cartographic information was in short supply.

I liked the idea of the Situationists who got their own chapter illustrated by the two authors attempting to meet up in London using a map of Paris. The Situationists were an anti-capitalist French group formed in 1957 who believed in making spectacles, and one way of doing this was to navigate a city at random, using the “wrong” map helps this process.

Technically interesting was the creation of the ITV regions in the UK, these arose from the 1954 legislation to end the BBC monopoly on broadcasting (the campaign for this used the slogan “freedom of the knob”!) . The regions were sometimes culturally illogical because transmitters were costly and worked by line of sight, this meant that, amongst other things, South Wales was grouped with Bristol. Also interesting that London had two franchises, one for weekdays which went to Thames and the other for weekends, won by London Weekend Television! The ITV regions were part of my youth, they went into decline when Channel 4 was launched in 1982, and further when the franchises were auctioned in the early nineties.

I’ve read before about the issues of mapping in India, it features in The Address Book by Deirdre Mask. In the city slums many streets are nameless largely as a result of their informal creation but also because the Indians were left with many colonial street names which they didn’t particularly like. In This Way Up addresses and directions in India provide an opportunity to talk about Google’s efforts to improve direction descriptions by the use of landmarks which is how people in Indian were found to describe routes. Actually this is more generally true, I may be vague about street names in my area but I definitely know the landmarks.

The Marshall Islands were very intensively mapped by the Americans prior to the post-war atomic bomb tests conducted there which led to the invention of the more powerful fusion bomb. The surveys were done so that the impact of those tests could be measured. They produced bigger explosions than expected leading to the evacuation of a number of the islands due to long-lived fallout, a number of smaller islands were entirely erased from the map. Also in this chapter were the stick maps that the Marshall Islanders used for navigation.

The final chapter talks about the coming of sat nav and the Google Map, tracing route finding technology from Roman itineraries to a medieval version of such; a scrolling itinerary linked to the turning of a cars wheels from the 1930s (the Iter Avto); audio itineraries, recorded on tape, from the early seventies; the Philips Carin digital map finally resulting in the sat nav we now today which was a luxury car add-on in the nineties and then in everyone’s hands in the form of the smartphone from 2009.

An excellent book for holiday reading, not so good if you are looking for something a little more academic.

Jun 19 2026

Book review: Alchemy by Philip Ball

I seem to have been on a run of illustrated books, perhaps as a result of regular visits to a local bookshop, illustrated books have more shelf appeal! This review is of Alchemy by Philip Ball with the lengthy subtitle; An Illustrated History of Elixirs, Experiments, and the birth of Modern Science. My copy is a larger format hardback book: a little shorter than A4 but about as wide. The illustrations are well-reproduced and mixed with the text although each chapter finishes with a series of illustrations with captions.

The book is divided into nine thematic chapters which are very roughly in chronological order. They cover the origins of alchemy, key interests of alchemists, laboratory equipment and the transition to modern chemistry with a final chapter on alchemy in culture.

Ancient Egyptians were key to early alchemy, making sophisticated glassware by the mid to late 15th century BC – the earliest glass dates to 2500BC. They were also making a wide range of chemical preparations including dyes, glazes and cosmetics.

The earliest Egyptian texts regarding alchemy date to the 3rd century AD, they were subsequently translated and greatly expanded by Islamic scholars towards the end of the first millennium from there they entered Europe during the Renaissance. Alchemists were also active in India and China from around at least the beginning of the Current Era.

Alchemy seems to have been prone to poorly attributed texts. For example, many texts are attributed to Jabir ibn Hayyan who probably lived in the 9th century – the broader corpus which he can’t have written is referred to as by “pseudo-Geber”. I wonder whether this issue is more widespread in early writing – a result of the pre-print mechanisms of publishing – rather than just an issue with alchemy.

In common with other scientific and artistic enterprises, alchemists often relied on royal patronage – Holy Roman Emperor Rudolf II (1552-1612) was a keen patron of alchemy in Prague.

Alchemy led to the birth of the laboratory as a separate space filled with a range of equipment which looks familiar even now. A variety of heat sources were central to this, alchemists were referred to as “puffers” as a result of their use of bellows to drive furnaces. The crucible, found in the lab today, comes from the Latin for “little place of torment”! Crucibles from the Hesse region of Germany were particularly sought after – it seems the local clay was very conducive to making crucibles. The bain-marie was invented as an alchemical tool by a, possibly mythical, female alchemist. Distillation, an important process even now, goes back to the 2nd millennium BC.

Converting other metals into gold, transmutation, was a primary concern for Western alchemists for pretty much the entire period that alchemists existed. The earliest bronze, made around 3500BC, was made by heating mixtures of ores not the pure metal, pure tin – one of the components of bronze, was not isolated until 1800BC. Our modern idea of elements dates is fairly recent, dating back to the 17th century. In the beginning the different elemental metals were not easily distinguishable from mixtures or even other elemental metals. Metal workers knew that rocks could be transformed to metals, and that metals could themselves could be transformed.

So why not transmutation? Even Robert Boyle, writing in the 17th century, was not convinced that transmutation was impossible.

Once elements were “discovered” it was realised that converting one element into another element (gold) is impossible. There is a proviso here though, 20th century atomic physics shows that elements can be transformed into other elements by nuclear processes but not by the chemical processes to which alchemists had access. As the physicist Ernest Rutherford said to his colleague Frederick Soddy “For Mike’s sake, Soddy, don’t call it transmutation. They’ll have our heads off as alchemists!”.

Transmutation was not the only subject of alchemical study, as well as broader chemical studies, in the East the search for elixirs to extend life was of more concern. Presumably more esoteric alchemical work sat alongside what we would now consider to be industrial chemistry.

In the West Paracelsus was creating a new sort of medicine based on chemistry rather than the four humours of ancient Greece. Philip Ball has written a biography of Paracelsus which I reviewed here. There’s a parallel here with the alchemists starting to break away from the classical elements (earth, water, fire, air, and aether) – in the same way that Copernicus and Galileo were breaking away from the Ptolemaic model of the universe.

It’s worth noting that the ability to make gold from other metals was potentially disastrous from an economic point of view – attempting to make gold was banned by both the Pope and Henry IV in the 14th and 15th centuries. The search for the philosopher’s stone (a material to carry out transmutation) came to be seen outside alchemy as both a fraudulent activity for some alchemists and a road to ruin for others, it was a byword for obsessive pursuits. Esotericism was long a feature of alchemy, the idea of keeping knowledge only for select adepts.

Throughout this review I have struggled as to when to write “alchemy” and when “chemistry”. Robert Boyle’s 1661, The Skeptical Chymist is often cited as a polemic against alchemy but it was more an effort to identify what was good and what was bad in alchemy to build what was to become chemistry. Some 20th century historians of science were dismissive of alchemy, seeing it as mysticism, hopeless causes and fraud perhaps influenced by the alchemy revival in the 19th century, which focussed on the spiritual side of alchemy. The alchemy Ball describes is one of chemicals, processes and a system of the world which transformed into modern chemistry through the 17th and 18th century with the loss of its mystical, and fraudulent elements.

Alchemy has always been referenced in wider culture, we still talk about alchemy now to reference processes which are almost magical in their effectiveness. I enjoyed this book, it has prompted me to seek out more books about alchemy – Ball includes a useful list of further reading.