Apr 202018

On this date in 1862, Louis Pasteur (and colleagues) concluded and published a series of experiments that definitively refuted the theory of spontaneous generation: the notion that living organisms can be generated by inanimate substances. Spontaneous generation was the dominant theory for thousands of years, and it’s not hard to understand why. When I tried to germinate avocado seeds in water in Myanmar for a school project, I had to dump the water constantly because every few days you could see mosquito larvae swimming in it. Where did they come from? Rotting meat frequently breeds maggots; old fruit seems to generate fruit flies. You need a good microscope, and controlled experiments, to figure out that living things are generated only by living things that are alike. Pasteur settled the matter, although there were holdouts for a while.

In the 6th and 5th centuries BCE, Greek philosophers, called physiologoi (φυσιολόγοι) that is, investigators of “nature” (φυσις – from which we get “physics”), attempted to give natural explanations of phenomena that had previously been ascribed to the agency of the gods. The physiologoi sought the material principle or arche (ἀρχή) of things, emphasizing the rational unity of the external world and rejecting theological or supernatural explanations. Anaximander, who believed that all things arose from the elemental nature of the universe, the apeiron (ἄπειρον) or the “unbounded” or “infinite,” was likely the first Western thinker to propose that life developed spontaneously from nonliving matter. The primal chaos of the apeiron, eternally in motion, served as a substratum in which elemental opposites (e.g., wet and dry, hot and cold) generated and shaped the many and varied things in the world. According to Hippolytus of Rome in the 3rd century CE, Anaximander claimed that fish or fish-like creatures were first formed in the “wet” when acted on by the heat of the sun and that these aquatic creatures gave rise to human beings. Censorinus, writing in the 3rd century, reports:

Anaximander of Miletus considered that from warmed up water and earth emerged either fish or entirely fishlike animals. Inside these animals, men took form and embryos were held prisoners until puberty; only then, after these animals burst open, could men and women come out, now able to feed themselves.

Anaximenes, a pupil of Anaximander, thought that air was the element that imparted life and endowed creatures with motion and thought. He proposed that plants and animals, including human beings, arose from a primordial terrestrial slime, a mixture of earth and water, combined with the sun’s heat. Anaxagoras, too, believed that life emerged from a terrestrial slime. However, he held that the seeds of plants existed in the air from the beginning, and those of animals in the aether. Xenophanes traced the origin of man back to the transitional period between the fluid stage of the earth and the formation of land, under the influence of the sun.

In what has occasionally been seen as a prefiguration of a concept of natural selection, Empedocles accepted the spontaneous generation of life but held that different forms, made up of differing combinations of parts, spontaneously arose as though by trial and error: successful combinations formed the species we now see, whereas unsuccessful forms failed to reproduce.

Aristotle proposed that in sexual reproduction, the child inherits form (eidos) from the father and matter from the mother, as well as πνεῦμα (pneuma) – breath, life, or spirit – either from the father or from the environment. In spontaneous generation, the environment could effectively replace the parents’ contributions of form, matter, and pneuma:

Now there is one property that animals are found to have in common with plants. For some plants are generated from the seed of plants, whilst other plants are self-generated through the formation of some elemental principle similar to a seed; and of these latter plants some derive their nutriment from the ground, whilst others grow inside other plants … So with animals, some spring from parent animals according to their kind, whilst others grow spontaneously and not from kindred stock; and of these instances of spontaneous generation some come from putrefying earth or vegetable matter, as is the case with a number of insects, while others are spontaneously generated in the inside of animals out of the secretions of their several organs.

(History of Animals, Book V, Part 1)

I first came across this notion when I studied Virgil’s Georgics, Book IV, on bee keeping. Virgil advises the following, if a bee keeper loses his stock:

First they choose a narrow place, small enough for this purpose:
they enclose it with a confined roof of tiles, walls close together,
and add four slanting window lights facing the four winds.

Then they search out a bullock, just jutting his horns out
of a two-year-old’s forehead: the breath from both its nostrils
and its mouth is stifled despite its struggles: it’s beaten to death,
and its flesh pounded to a pulp through the intact hide.

They leave it lying like this in prison, and strew broken branches
under its flanks, thyme and fresh rosemary.
This is done when the Westerlies begin to stir the waves
before the meadows brighten with their new colours,
before the twittering swallow hangs her nest from the eaves.

Meanwhile the moisture, warming in the softened bone, ferments,
and creatures, of a type marvelous to see, swarm together,
without feet at first, but soon with whirring wings as well,
and more and more try the clear air, until they burst out,
like rain pouring from summer clouds,
or arrows from the twanging bows,
whenever the lightly-armed Parthians first join battle.

Spontaneous generation is discussed as a fact in literature well into the Renaissance. Shakespeare says snakes and crocodiles form from the mud of the Nile:

Your serpent of Egypt is bred now of your mud by the operation of your sun. So is your crocodile.  

(Anthony and Cleopatra Act 2 scene 7)

Izaak Walton agrees when he says that eels “as rats and mice, and many other living creatures, are bred in Egypt, by the sun’s heat when it shines upon the overflowing of the river.”

Jan Baptist van Helmont (1580–1644) used experimental techniques, such as growing a willow for five years and showing it increased mass while the soil showed a trivial decrease in comparison. He attributed the increase of mass to the absorption of water. His notes also describe a recipe for mice (a piece of soiled cloth plus wheat for 21 days) and scorpions (basil, placed between two bricks and left in sunlight). His notes suggest he may even have tried these things.

The ancient beliefs were subjected to testing starting in the 17th century. In 1668, Francesco Redi challenged the idea that maggots arose spontaneously from rotting meat. In the first major experiment to challenge spontaneous generation, he placed meat in a variety of sealed, open, and partially covered containers. Realizing that the sealed containers were deprived of air, he used “fine Naples veil”, and observed no worm on the meat, but they appeared on the cloth. Redi used his experiments to support the preexistence theory put forth by the Church at that time, which maintained that living things originated from parents. Pier Antonio Micheli, around 1729, observed that when fungal spores were placed on slices of melon the same type of fungi were produced that the spores came from, and from this observation he noted that fungi did not arise from spontaneous generation.

In 1745, John Needham performed a series of experiments on boiled broths. Believing that boiling would kill all living things, he showed that when sealed right after boiling, the broths would cloud, allowing the belief in spontaneous generation to persist. His studies were rigorously scrutinized by his peers and many of them agreed.

Lazzaro Spallanzani modified the Needham experiment in 1768, attempting to exclude the possibility of introducing a contaminating factor between boiling and sealing. His technique involved boiling the broth in a sealed container with the air partially evacuated to prevent explosions. Although he did not see growth, the exclusion of air left the question of whether air was an essential factor in spontaneous generation. However, by that time there was already widespread skepticism among major scientists, to the principle of spontaneous generation. Observation was increasingly demonstrating that whenever there was sufficiently careful investigation of mechanisms of biological reproduction, it was plain that processes involved basing of new structures on existing complex structures, rather from chaotic muds or dead materials.

Louis Pasteur’s 1859 experiment is widely seen as having settled the question of spontaneous generation. He boiled a meat broth in a flask that he invented called the swan-necked flask (because ithad a long neck that curved downward, like that of a swan). The idea was that the bend in the neck prevented falling particles from reaching the broth, while still allowing the free flow of air. The flask remained free of growth for an extended period. When the flask was turned so that particles could fall down the bends, the broth quickly became clouded. A flask in which broth was boiled and immediately exposed to air, became clouded quickly. Minority objections to the conclusiveness of the experiments were persistent, however, and subsequent, more rigorous, experiments were needed to bring the question to an end for the die-hards. Hey – we still have flat earthers.

The obvious ingredient for today’s celebratory recipe is Lyle’s golden syrup. The label has the ancient slogan on it, “Out of the strong came forth sweetness,” a reference to a riddle put by Samson in Judges 14:14, the answer to which is that dead lions propagate honey bees. Here is the recipe for treacle tart taken from the Lyle’s website (unedited):


Lyle’s Treacle Tart



295g Plain flour, plus extra for dusting
165g Unsalted butter (chilled + cubed)
4½ tbsp Cold water
Pinch of salt


450g Lyle’s Golden Syrup
25g Unsalted butter
1 Large egg
3 tbsp Double cream
2 sachets Dr Oetker Lemon Ready Zest
30g breadcrumbs (increase to 80g for a denser mixture)
Crème fraîche, for serving


Pulse the flour, butter and salt in a blender until the mixture resembles large crumbs. Add the water and briefly blend until it comes together in a ball – then wrap in cling film and chill for 20 minutes.

Cut off one-third of the pastry and set aside for the lattice top. Roll the rest of pastry out on a lightly floured surface to about 4cm (1½”) bigger than a loose-bottomed tart tin, 22cm (9”) x 3.5cm (1½”) deep. Line the tin with pastry, trim the excess and lightly prick with a fork, then chill for 30 minutes. Add the excess to the pastry set aside for the lattice top.

Preheat the oven to 190°C/170° Fan, 375°F, Gas 5. Lay some baking parchment in the tin over the pastry and then put your baking beans in, over the parchment. Place in the oven and pre-bake for 15 minutes on the middle shelf. Remove the paper and beans and bake for a further 8-10 minutes to dry the pastry out. Remove the tart from the oven and put it on a baking tray. Reduce the oven temperature down to 180°C/160°Fan, 350°F, Gas 4, ready for later.

Roll the extra lattice top pastry out thinly and set aside on a tray to chill in the fridge for about 20-30 minutes – this makes it easier to handle.

Gently warm the Lyle’s Golden Syrup in a pan over a low heat, remove, then add the butter and stir until melted. Leave to cool a little. Using a fork, beat the egg and cream together in a separate bowl, then quickly beat in the syrup mixture along with the lemon zest and crumbs. Pour into the pastry case.

Remove the pastry from the fridge and cut into 10 strips of 1cm width which are long to overhang the edges of the tart tin.

Lay 5 parallel strips equally spaced over the tart. Fold back every other strip and place one strip of dough perpendicular to the parallel strips. Unfold the folded strips over the perpendicular strip. Now take the parallel strips that are running underneath the perpendicular strip and fold them back over. Lay down a second perpendicular strip (evenly spaced) and unfold the folded parallel strips.

Continue this process until all 10 strips have been placed. Trim the edges of the strips for a neat finish to fit inside the tart.

Bake on the middle shelf for 45-50 minutes until richly brown and set. (The filling will still be a bit wobbly but it will firm up on cooling.) Remove, leave to cool until warm, then remove from the tin, slide onto a plate and serve.

Oct 152014


Today is the birthday (70 BCE) of Publius Vergilius Maro, usually called Virgil in English, an ancient Roman poet of the Augustan period. He is known for three major works of Latin literature, the Eclogues (or Bucolics), the Georgics, and the epic Aeneid. A number of minor poems, collected in the Appendix Vergiliana, are sometimes attributed to him, but they are likely not authentic.

Virgil is traditionally ranked as one of Rome’s greatest poets. His Aeneid has been deemed the national epic of ancient Rome from the time of its composition to the present day. It was modeled after Homer’s Iliad and Odyssey, following the Trojan refugee Aeneas as he struggles to fulfill his destiny and arrive on the shores of Italy where he founded Rome. Virgil’s work has had wide and deep influence on Western literature, most notably the Divine Comedy of Dante, in which Virgil appears as Dante’s guide through hell and purgatory.


Virgil’s biographical tradition is thought to depend on a lost biography by Varius, Virgil’s editor, which was incorporated into the biography by Suetonius and the commentaries of Servius and Donatus, the two great commentators on Virgil’s poetry. Although the commentaries no doubt record much factual information about Virgil, some of their evidence can be shown to rely on inferences made from his poetry and allegorizing; thus, Virgil’s biographical tradition remains problematic.

The tradition holds that Virgil was born in the village of Andes, near Mantua in Cisalpine Gaul. Scholars suggest Etruscan, Umbrian, or even Celtic descent by examining the linguistic or ethnic markers of the region. Analysis of his name has led to beliefs that he descended from earlier Roman colonists. Modern speculation ultimately is not supported by narrative evidence either from his own writings or his later biographers. Macrobius says that Virgil’s father was of a humble background; however, scholars generally believe that Virgil was from an equestrian landowning family which could afford to give him an education. He attended schools in Cremona, Mediolanum, Rome and Naples. After considering briefly a career in rhetoric and law, the young Virgil turned his talents to poetry.


According to the commentators, Virgil received his first education when he was five years old and he later went to Cremona, Milan, and finally Rome to study rhetoric, medicine, and astronomy, which he soon abandoned for philosophy. From Virgil’s admiring references to the neoteric (new poets) writers Pollio and Cinna, it has been inferred that he was, for a time, associated with Catullus’ neoteric circle. However schoolmates considered Virgil extremely shy and reserved, according to Servius, and he was nicknamed “Parthenias” or “maiden” because of his social aloofness. Virgil seems to have suffered bad health throughout his life and in some ways lived the life of an invalid. According to the Catalepton, while in the Epicurean school of Siro the Epicurean at Naples, he began to write poetry. A group of small works attributed to the youthful Virgil by the commentators survive collected under the title Appendix Vergiliana, but are largely considered spurious by scholars. One, the Catalepton, consists of fourteen short poems, some of which may be Virgil’s, and another, a short narrative poem titled the Culex (“The Gnat”), was attributed to Virgil as early as the 1st century CE.

Much has been written about the Aeneid, but I am going to pass over it in favor of the Georgics. I studied both in Latin in school, and without hesitation I will assert that I find the Aeneid dull for several reasons. To begin with it pales in comparison with Homer in my estimation. The imagery is forced and leaden where Homer is bright and spontaneous. Second, its obvious fawning admiration for the emperor Augustus and the attempt to link his glory with the founding of Rome leaves me cold. By contrast I find the Georgics fascinating in large part because of their insights into Roman agriculture and husbandry (perfectly pertinent for a foodie blog).


After the publication of the Eclogues (probably before 37 BCE), Virgil became part of the circle of Maecenas, Octavian’s capable agent d’affaires who sought to counter sympathy for Antony among the leading families by rallying Roman literary figures to Octavian’s side. Virgil seems to have made connexions with many of the other leading literary figures of the time, including Horace, in whose poetry he is often mentioned, and Varius Rufus, who later helped finish the Aeneid.

At Maecenas’ insistence (according to the tradition) Virgil spent the ensuing years (perhaps 37–29 BC) on the longer didactic hexameter poem called the Georgics (from Greek, “On Working the Earth”) which he dedicated to Maecenas. The ostensible theme of the Georgics is instruction in the methods of running a farm. In handling this theme, Virgil follows in the didactic (instructive) tradition of the Greek poet Hesiod’s Works and Days and several works of the later Hellenistic poets.


The four books of the Georgics focus respectively on raising crops and trees (1 and 2), livestock and horses (3), and beekeeping and the qualities of bees (4). Significant passages include the beloved Laus Italiae of Book 2, the prologue description of the temple in Book 3, and the description of the plague at the end of Book 3. Book 4 concludes with a long mythological narrative, in the form of an epyllion, a short discrete narrative within a longer work, which describes vividly the discovery of beekeeping by Aristaeus and the story of Orpheus’ journey to the underworld. Ancient scholars, such as Servius, conjectured that the Aristaeus episode replaced a long section in praise of Virgil’s friend, the poet Gallus, who was disgraced by Augustus and committed suicide in 26 BC. Augustus is supposed to have ordered the section to be replaced.

A major critical issue in considering the Georgics is the assessment of tone; Virgil seems to waver between optimism and pessimism, sparking a great deal of debate on the poem’s intentions. With the Georgics Virgil is credited with laying the foundations for later didactic poetry. The biographical tradition says that Virgil and Maecenas took turns reading the Georgics to Octavian upon his return from defeating Antony and Cleopatra at the Battle of Actium in 31 BC.


Book One

Virgil begins his poem with a summary of the four books, followed by a prayer to various agricultural deities as well as Augustus himself. It takes as its model the work on farming by Varro, but differs from it in important ways. Numerous technical passages fill out the first half of Book 1; of particular interest are lines 160–175, where Virgil describes the plough. In the succession of ages, whose model is ultimately Hesiod, the age of Jupiter and its relation to the golden age and the current age of man are crafted with deliberate tension. Of chief importance is the contribution of labor to the success or failure of mankind’s endeavors, agricultural or otherwise. The book comes to one climax with the description of a great storm in lines 311–50, which brings all of man’s efforts to naught. After detailing various weather-signs, Virgil ends with an enumeration of the portents associated with Caesar’s assassination and civil war; only Octavian offers any hope of salvation.

Book Two

Prominent themes of the second book include agriculture as mankind’s struggle against a hostile natural world, often described in violent terms, and the ages of Saturn and Jupiter Like the first book, it begins with a poem addressing the divinities associated with the matters about to be discussed: viticulture, trees, and the olive. In the next hundred lines Virgil treats forest and fruit trees. Their propagation and growth are described in detail, with a contrast drawn between methods that are natural and those that require human intervention. Three sections on grafting are of particular interest: presented as marvels of man’s alteration of nature, many of the examples Virgil gives are unlikely or impossible. Also included is a catalogue of the world’s trees, set forth in rapid succession, and other products of various lands. Perhaps the most famous passage of the poem, the Laudes Italiae or Praises of Italy, is introduced by way of a comparison with foreign marvels: despite all of those, no land is as praiseworthy as Italy. A point of cultural interest is a reference to Ascra in line 176, which an ancient reader would have known as the hometown of Hesiod. Next comes the care of vines, culminating in a vivid scene of their destruction by fire; then advice on when to plant vines, and therein the other famous passage of the second book, the Praises of Spring. These depict the growth and beauty that accompany spring’s arrival. The poet then returns to didactic narrative with yet more on vines, emphasizing their fragility and intensive care. A warning about animal damage provides occasion for an explanation of why goats are sacrificed to Bacchus. The olive tree is then presented in contrast to the vine: it requires little effort on the part of the farmer. The next subject, at last turning away from the vine, is other kinds of trees: those that produce fruit and those that have useful wood. Then Virgil again returns to grapevines, recalling the myth of the battle of the Lapiths and Centaurs in a passage known as the Vituperation of Vines. The remainder of the book is devoted to extolling the simple country life over the corruptness of the city.

Book Three

The third book is chiefly and ostensibly concerned with animal husbandry. It consists of two principal parts, the first half is devoted to the selection of breed stock and the breeding of horses and cattle. It concludes with a description of the furor induced in all animals by sexual desire. The second half of the book is devoted to the care and protection of sheep and goats and their byproducts. It concludes with a description of the havoc and devastation caused by a plague in Noricum. Both halves begin with a short prologue called a proem. The poems invoke Greek and Italian gods and address such issues as Virgil’s intention to honor both Caesar and his patron Maecenas, as well as his lofty poetic aspirations and the difficulty of the material to follow. Many have observed the parallels between the dramatic endings of each half of this book and the irresistible power of their respective themes of love and death.

Book Four

Book four, a tonal counterpart to Book two, is divided approximately in half; the first half (1–280) is didactic and deals with the life and habits of bees, supposedly a model for human society. Bees resemble humans in that they labor, are devoted to a leader, and give their lives for the sake of the community, but they lack the arts and love. In spite of their labor the bees perish and the entire colony dies. The restoration of the bees is accomplished by bugonia, spontaneous rebirth from the carcass of an ox. This process is described twice in the second half (281–568) and frames the Aristaeus epyllion beginning at line 315. The tone of the book changes from didactic to epic and elegiac in this epyllion, which contains within it the story of Orpheus and Eurydice. Aristaeus, after losing his bees, descends to the home of his mother, the nymph Cyrene, where he is given instructions on how to restore his colonies. He must capture the seer, Proteus, and force him to reveal which divine spirit he angered and how to restore his bee colonies. After binding Proteus (who changes into many forms to no avail), Aristaeus is told by the seer that he angered the nymphs by causing the death of the nymph Eurydice, wife of Orpheus. Proteus describes the descent of Orpheus into the underworld to retrieve Eurydice, the backward look that caused her return to Tartarus, and at last Orpheus’ death at the hands of the Ciconian women. Book four concludes with an eight-line sphragis or seal in which Virgil contrasts his life of poetry with that of Octavian the general.


To celebrate Virgil I give you a recipe from Apicius, the late 4th century Roman cook book that I have used before. Apicius is a text to be used in the kitchen. In the earliest printed editions, it was most usually given the overall title De re coquinaria (“On the Subject of Cooking”) and attributed to an otherwise unknown Caelius Apicius, an invention based on the fact that one of the two manuscripts is headed with the words “API CAE”.

The foods described in the book are useful for reconstructing the dietary habits of the ancient world around the Mediterranean Basin, since many of the foods identified with that region today—tomatoes, pasta—were not available in antiquity. But the recipes are geared for the wealthiest classes, and a few contain what were exotic ingredients at that time (e.g., flamingo).

Here is a recipe for lamb or goat stew incorporating ingredients whose cultivation and husbandry are described in Georgics:

ALITER HAEDINAM SIVE AGNINAM EXCALDATAM: mittes in caccabum copadia. cepam, coriandrum minutatim succides, teres piper, ligusticum, cuminum, liquamen, oleum, vinum. coques, exinanies in patina, amulo obligas. [Aliter haedinam sive agninam excaldatam] <agnina> a crudo trituram mortario accipere debet, caprina autem cum coquitur accipit trituram.

HOT KID OR LAMB STEW. Put the pieces of meat into a pan. Finely chop an onion and coriander, pound pepper, lovage, cumin, liquamen, oil, and wine. Cook, turn out into a shallow pan, thicken with wheat starch. If you take lamb you should add the contents of the mortar while the meat is still raw, if kid, add it while it is cooking.


Not having a kitchen at the moment I cannot make an effort to recreate this dish, but it looks fairly straightforward. Cut the meat into bite sized chunks. Make a marinade of onion, cilantro, peppercorns, lovage, cumin, liquamen substitute (1 tablespoon of Asian fermented fish sauce in a cup of water), extra virgin olive oil, and Italian red wine in a blender, and marinate the meat overnight in the refrigerator (see “marinating” under my Hints tab). I’m not sure why Apicius suggests this for lamb but not for kid. If you want to be authentic you can omit this step for kid. Bring the meat and marinade to a slow simmer and skim off any scum at the outset. Simmer covered for about 2 hours, or until the meat is fully tender. Thicken the sauce with a slurry of flour and water if necessary. Serve with your choice of Old World vegetables and crusty Italian bread. You will find my Roman recipe for broad beans here: