Baghdad battery: in the ancient world could use electroplating

Some finds of archaeologists still cause a lot of questions and are the subject of unceasing disputes between historians. For example, some experts consider the Baghdad battery, which is stored in the National Museum of Iraq, to be an ancient galvanic cell and even prove it by conducting simple experiments. But skeptical scientists believe that an item that is more than 2000 years old cannot be a galvanic cell in any way, but just a vessel for storing scrolls.

The Baghdad battery was found during excavations of the ancient Parthian settlement of Khujut-Rabu, in Iraq. And the first researcher of this mysterious subject was the German archaeologist Wilhelm Koenig. This item resembles a hollow vessel 13 centimeters high, inside of which there is a copper cylinder with an iron rod. The neck of the vessel was covered with bitumen, through which passed a metal rod with traces of corrosion.

Initially, the find was attributed to the period of the Parthian kingdom (III century BC - III century AD), but later, with a detailed analysis of the material of the vessel, it was assumed that the find belongs to the period of the Sassanian kingdom (III- VII century), but in any case, the vessel was of venerable age. Despite this, the find's author Wilhelm Koenig put forward a bold assumption: a strange vessel could be the simplest galvanic cell. With this device, the ancient masters could, using the galvanization method, apply the thinnest layers of gold and silver. Examples of such products among the artifacts of the Ancient world can be found abound.

Koenig's assumption has been repeatedly confirmed in practice, including by several respected scientists. In order for such a "battery" to work, you need acid or alkali (electrolyte), which would create an electrical voltage. Scientists conducted experiments with simple acids, which are known to people from antiquity. As a result of experiments, wine vinegar or lemon juice provided a voltage of 0.5 to 2 volts, and this was quite enough to use the vessel in the process of electroplating.

But the Baghdad battery remains the only item of this kind at the moment, nothing like this has ever been found. For this reason, most scientists have so far refrained from any conclusions, and an unusual subject has remained a mystery.