For nearly 200 years, archaeologists have been puzzled by a mysterious brown stain on the traditional Greek Parthenon temple in Greece. Now, researchers have carried out new scientific analyses, and their verdict is evident: The thriller stays.

On the Nationwide Museum in Copenhagen, Denmark, there’s a marble head that was as soon as a part of the traditional Greek Parthenon temple on the Acropolis in Athens. The pinnacle initially belonged to a centaur determine and was a part of a scene depicting the Greek mythological Lapiths’ battle in opposition to the centaurs (legendary creatures that have been half-horse, half-human).

For causes which have but to be defined, components of the centaur head are coated with a skinny brown movie, as are a number of different marble fragments from the Parthenon.

Pondering the Doubtful Brown Substance

The mysterious brown movie was first examined by the British Museum in 1830.

Again then, makes an attempt have been made to find out if the colour originated from historic paint, nevertheless it was finally concluded that it is perhaps a results of a chemical response between the marble and the air, or that the marble contained iron particles that had migrated to the floor, coloring it brown.

• The Mentor Shipwreck and the Disastrous Journey of the Parthenon Marbles to Britain
• Historic Greek Science and Expertise – From Antikythera to Pharos

The Centaur head on the Nationwide Museum in Copenhagen, entrance view. (Courtesy of The Nationwide Museum of Denmark/Heritage Science Journal)

Oxalic Acid, Algae and Fungi

“There have been many makes an attempt to clarify the peculiar brown movie. In 1851, German chemist, Justus von Liebig, carried out the very first scientific investigation and decided that the brown movie contained oxalates — salts of oxalic acid. This has been confirmed by later analyses, however the origin of the oxalates has remained a thriller,” says Professor emeritus Kaare Lund Rasmussen, an professional in chemical analyses of historic and archaeological artifacts, Division of Physics, Chemistry and Pharmacy, College of Southern Denmark.

Together with College of Southern Denmark colleagues Frank Kjeldsen and Vladimir Gorshkov from the Division of Biochemistry and Molecular Biology, Bodil Bundgaard Rasmussen, former head of the Antiquities Assortment on the Nationwide Museum of Denmark, Thomas Delbey from Cranfield College in England, and Ilaria Bonaduce from the College of Pisa, Italy, he has revealed a scientific article describing the results of their investigations into the brown-colored centaur head from the Nationwide Museum.

• The Parthenon: An Epic Monument Or a Thriller in Measurements?
• Centaurs in Greek Mythology: From the Iliad to Sagittarius and Harry Potter

The centaur head on the Nationwide Museum in Copenhagen.  a: entrance view;  b: rear view. The brown stains are clearly seen. (Courtesy of The Nationwide Museum of Denmark/Heritage Science Journal)

“We particularly wished to look at whether or not the brown movie may have been shaped by some organic organism, akin to lichen, micro organism, algae, or fungi. This principle had been recommended earlier than, however no particular organism had been recognized. The identical goes for the idea that it could possibly be remnants of utilized paint — maybe to guard or tone the marble floor,” says Kaare Lund Rasmussen.

For his or her investigations, the analysis group was allowed to take 5 small samples from the again of the centaur head.

These samples underwent varied analyses in SDU’s laboratories, together with protein evaluation and so-called Laser Ablation Inductively Coupled Plasma Mass Spectrometry.

“We discovered no traces of organic matter within the brown layers — solely from our personal fingerprints and maybe a hen egg that broke on the marble in historic occasions. This does not show that there by no means was a organic substance, nevertheless it considerably reduces the chance, making the idea of a organic organism much less possible now,” says Kaare Lund Rasmussen.

Equally, it’s now much less possible that the marble floor was painted or preserved, based on the researchers, who additionally particularly looked for traces of paint.

Historic paints have been usually based mostly on pure merchandise akin to eggs, milk, and bones, and no traces of such elements have been discovered within the brown stain alone.

The Thriller Stays

Via their investigations, the analysis group additionally found that the brown movie consists of two separate layers.

These two layers are roughly equally thick, round 50 micrometers every, they usually differ when it comes to hint factor composition.

Nevertheless, each layers comprise a mix of the oxalate minerals weddellite and whewellite.

The truth that there are two distinct layers argues in opposition to the idea that they have been created by the migration of fabric, akin to iron particles, from the inside of the marble.

It additionally contradicts the idea that they resulted from a response with the air.

Air air pollution can be unlikely for an additional cause; the centaur head has been indoors in Copenhagen since earlier than the fashionable industrialization started within the 18th century.

Actually, this makes the heads on the Nationwide Museum of Denmark significantly precious in comparison with the marble items on the Acropolis, of which some have solely just lately been introduced indoors.

“As there are two totally different brown layers with totally different chemical compositions, it’s doubtless that they’ve totally different origins. This might recommend that somebody utilized paint or a conservation therapy, however since we have not discovered traces of such substances, the brown shade stays a thriller,” concludes Kaare Lund Rasmussen.

Prime picture: The Parthenon Centaur displayed within the Nationwide Museum in Copenhagen. Supply: Courtesy of The Nationwide Museum of Denmark/Heritage Science Journal

The article ‘Regardless of Intensive Scientific Analyses, This Centaur Head Stays a Thriller’ was initially revealed on Science Each day. Supply: Materials supplied by University of Southern Denmark. Unique written by Birgitte Svennevig. Notice: Content material could also be edited for model and size.