Sep 282017

On this date in 1928 Sir Alexander Fleming, according to his own account much later, noticed a bacteria-killing mold growing on a petri dish in his laboratory thus discovering what he later called penicillin. There are many BIG MOMENTS like this documented in the history of ideas that are not really quite the turning points they seem to be in hindsight.  The actual development of effective antibiotics was years away from Fleming’s chance discovery, and there’s some doubt as to how much it was a pure accident.  Even so, we can celebrate the day anyway.

For centuries, but especially in the late 19th century, there had been numerous accounts by scientists and physicians on the antibacterial properties of different types of molds, including the mold penicillium, but they were unable to discern what process or ingredient was causing the effect. The traditional version of Fleming’s discovery paints it as a serendipitous accident, but many skeptics have questioned the extent of the serendipity. While it is likely true that by chance Fleming noticed a petri dish containing Staphylococcus, which had been mistakenly left open, had been contaminated by blue-green mold from an open window in his laboratory in the basement of St Mary’s Hospital in London (now part of Imperial College), and that there was a halo of inhibited bacterial growth around the mold, it was not a groundbreaking conclusion that the mold released a substance that repressed the growth and caused lysing (rupturing of the cell walls) of the bacteria. Surely he would have known of previous accounts of the antibacterial properties of molds.

Once Fleming made his “discovery” he grew a pure culture of the intrusive growth and found that it was a Penicillium mold, now known as Penicillium chrysogenum. Fleming coined the term “penicillin” to describe the filtrate of a broth culture of the Penicillium mould. Fleming asked C. J. La Touche to help identify the mold, which he incorrectly identified as Penicillium rubrum (later corrected by Charles Thom). He expressed initial optimism that penicillin would be a useful disinfectant, because of its high potency and minimal toxicity in comparison to antiseptics of the day, and noted its laboratory value in the isolation of Bacillus influenzae (now called Haemophilus influenzae).

Fleming was a famously poor communicator and orator, which meant his findings were not initially given much attention. He was unable to convince a chemist to help him extract and stabilize the antibacterial compound found in the broth filtrate. Despite this, he remained interested in the potential use of penicillin and presented a paper entitled “A Medium for the Isolation of Pfeiffer’s Bacillus” to the Medical Research Club of London, which was met with little interest and even less enthusiasm by his peers. Had Fleming been more successful at making other scientists interested in his work, penicillin for medicinal use would probably have been developed years earlier.

Despite the lack of interest of his fellow scientists, he did conduct several more experiments on the antibiotic substance he discovered. The most important result proved it was nontoxic in humans by first performing toxicity tests in animals and then on humans. His following experiments on penicillin’s response to heat and pH allowed Fleming to increase the stability of the compound. The one test that modern scientists would find missing from his work was the test of penicillin on an infected animal, the results of which would likely have sparked great interest in penicillin and sped its development by almost a decade.

Molecular model of Penicillin by Dorothy Hodgkin, c.1945. Front three quarter. Graduated grey background.

In 1930, Cecil George Paine, a pathologist at the Royal Infirmary in Sheffield, attempted to use penicillin to treat sycosis barbae, eruptions in beard follicles, but was unsuccessful. Moving on to ophthalmia neonatorum, a gonococcal infection in infants, he achieved the first recorded cure with penicillin, on November 25, 1930. He then cured four additional patients (one adult and three infants) of eye infections, but failed to cure a fifth.

In 1939, Australian scientist Howard Florey (later Baron Florey) and a team of researchers (Ernst Boris Chain, Edward Abraham, Arthur Duncan Gardner, Norman Heatley, M. Jennings, J. Orr-Ewing and G. Sanders) at the Sir William Dunn School of Pathology, University of Oxford made progress in showing the in vivo bactericidal action of penicillin. In 1940, they showed that penicillin effectively cured bacterial infection in mice. In 1941, they treated a policeman, Albert Alexander, with a severe face infection. His condition improved, but then supplies of penicillin ran out and he died. Subsequently, several other patients were treated successfully. In December 1942, survivors of the Cocoanut Grove fire in Boston were the first burn patients to be successfully treated with penicillin.

By late 1940, the Oxford team under Howard Florey had devised a method of mass-producing the drug, but yields remained low. In 1941, Florey and Heatley travelled to the US in order to interest pharmaceutical companies in producing the drug and inform them about their process. Florey and Chain shared the 1945 Nobel Prize in Medicine with Fleming for their work.

Several species of the genus Penicillium play a central role in the production of cheese and of various meat products. Penicillium molds are used for Blue cheeses in general. Penicillium camemberti and Penicillium roqueforti are the molds on Camembert, Brie, Roquefort, and a host of other cheeses. Penicillium nalgiovense is used to improve the taste of sausages and hams, and to prevent colonization by other molds and bacteria. Penicillium camemberti is one of the most common molds used for cheese production. It is used to make Camembert, Brie, Langres, Coulommiers and Cambozola. Colonies of P. camemberti form a hard, white crust on these cheeses, and is also responsible for giving them their distinctive taste.

With that information I’ll leave you to it. I’m thinking of camembert and salami on a crusty roll – probably toasted or grilled. I’m sure you’ll think of something.


Apr 262016


In the early afternoon on this date in 1803 a meteorite shower of more than 3000 fragments fell upon the town of L’Aigle in Normandy. Upon hearing of this event the French Academy of Sciences sent the young scientist Jean-Baptiste Biot to investigate. After painstaking work in the field he reported two kinds of evidence pointing to an extraterrestrial origin for the stones:

Physical evidence: the sudden appearance of many identical stones similar to other stones fallen from the sky in other places

Human evidence: a large number of witnesses who said they saw a “rain of stones thrown by a meteor.”


Biot drew a detailed map of the dispersal of the meteorites, and his subsequent impassioned paper describing how these stones must undoubtedly be of extraterrestrial origin effectively gave birth to the science of meteoritics. The L’Aigle event was a real milestone in the understanding of meteorites and their origins because at that time the mere existence of meteorites was hotly debated. The existence of stones falling from the sky had long been recognized, but their origin was controversial, with most commentators agreeing with Aristotle that they were terrestrial in origin. Eye-witness accounts were treated with great skepticism. They were generally dismissed as lies or delusions.


The meteorites that fell on L’Aigle were collected and sold or sent to numerous museums in Europe where they may still be seen.

aigle5 aigle3 aigle1

Most meteorite falls, such as at L’Aigle, are recovered on the basis of eyewitness accounts of the fireball or the impact of the objects on the ground, or both. Therefore, despite the fact that meteorites fall with virtually equal probability everywhere on Earth, verified meteorite falls tend to be concentrated in areas with high human population densities such as Europe, Japan, and northern India. As of April 2016, the Meteoritical Bulletin Database has listed 1,145 confirmed falls.

Meteorite falls may have occasionally led to cult worship historically. The cult in the Temple of Artemis at Ephesus, one of the Seven Wonders of the Ancient World, possibly originated with the observation of a meteorite that was taken by contemporaries to have fallen to the earth from the home of the gods. There are reports that a sacred stone was enshrined at the temple that may have been a meteorite.


In the 1970s, a stone meteorite was uncovered during an archaeological dig at Danebury Iron Age hillfort, Danebury England. It was found deposited part way down in an Iron Age pit (c. 1200 BCE). Since it must have been deliberately placed there, this could indicate one of the first known human finds of a meteorite in Europe.

Some Native Americans treated meteorites as ceremonial objects. In 1915, a 135-pound iron meteorite was found in a Sinagua (c. 1100–1200 AD) burial cyst near Camp Verde, Arizona, respectfully wrapped in a feather cloth. A small meteorite was found in a pottery jar in an old burial found at Pojoaque Pueblo, New Mexico. Archeologists report several other such instances, in the Southwest US and elsewhere, such as the discovery of Native American beads of meteoric iron found in Hopewell burial mounds, and the discovery of the Winona meteorite in a Native American stone-walled crypt. The oldest known iron artifacts are nine small beads hammered from meteoritic iron. They were found in northern Egypt and have been securely dated to 3200 BCE.

Indigenous peoples often prized iron-nickel meteorites as an easy, if limited, source of iron metal. For example, the Inuit used chips of the Cape York meteorite to form cutting edges for tools and spear tips.

Publishing is analogous to meteorite strikes. I know editors have seen my articles that they printed, but I have absolutely no idea how many have read them or what impact, if any, they have made. Ditto for my books. I know how many have sold, but no idea how many were read. This fact would be depressing if I cared. I am not trying to make money from my writing, or become famous.  I write because it pleases me.  If it pleases others, I am glad; if not, not.


L’Aigle is in Orne, a landlocked department in Normandy that is also the site of Camembert, the village that gives its name to the famous cheese. Coincidentally, camembert was first made around the time of the L’Aigle meteorite fall. Camembert was reputedly first made in 1791 by Marie Harel, a farmer from Normandy, following advice from a priest who came from Brie.

However, the origin of the cheese known today as camembert is more likely to rest with the beginnings of the industrialization of the cheesemaking process at the end of the 19th century. In 1890, an engineer, M. Ridel, devised the wooden box which was used to carry the cheese and helped to send it for longer distances, in particular to North America, where it became very popular. These boxes are still used today.

Before fungi were scientifically understood, the color of camembert rind was a matter of chance, most commonly blue-grey, with brown spots. From the early 20th century onwards, the rind has been more commonly pure white, but it was not until the mid-1970s that pure white became standard.

My discovery of camembert occurred in 1966 when I was an exchange student in France. Before that time my culinary tastes were extremely limited. Cheese, as far as I was concerned, was generic Cheddar. But when I lived in France it was my duty, along with Jean-Loup my exchange mate, to get the baguettes for the evening meal on our way home from school. We frequently bought some camembert as well, sliced it, and stuffed it into a baguette as a quick snack on the way home. That, and Jean-Loup’s mother’s cooking, changed my outlook on food for life.

So, why not do the same in tribute to the L’Aigle meteorite fall?  I just did.