Biblical Mysteries: Manna

Anyone who is even remotely familiar with the Old Testament knows about manna-- the supernatural food which fell from the heavens and nourished the Israelites during their forty years of wandering in the desert. And yet, thousands of years later, experts are still arguing about the true identity of this supposedly miraculous substance.

Before we weigh in on the debate, for the benefit of those not familiar with the Old Testament, let's go over the Biblical references. Manna is only described twice in the Old Testament; once in the Book of Exodus, and once again in the Book of Numbers.

In Exodus, manna is described as fine, flaky substance ("And when the layer of dew was gone up, behold upon the face of the wilderness a fine, scale-like thing, fine as the hoar-frost on the ground") which had be gathered up quickly before it spoiled, melted, or became infested with insects ("some of them left of it until the morning, and it bred worms, and rotted; and Moses was wroth with them... and they gathered it morning by morning, every man according to his eating; and as the sun waxed hot, it melted."). In Exodus, it is implied that the manna was white in color ("And the house of Israel called the name thereof Manna; and it was like coriander seed, white; and the taste of it was like wafers made with honey.")

In the Book of Numbers, manna is described as having the appearance of bdellium, which is the yellowish resin of the myrrh tree. Some skeptics point to this discrepancy as proof that manna was merely a legend, although dried coriander seeds do tend to be more yellow than white in color ("but now our soul is dried away; there is nothing at all; we have nought save this manna to look to... the manna was like coriander seed, and the appearance thereof as the appearance of bdellium... The people went about, and gathered it, and ground it in mills, or beat it in mortars, and seethed it in pots, and made cakes of it; and the taste of it was as the taste of a cake baked with oil.").

For centuries, a product known as manna has been sold in many Middle Eastern markets. This form of manna is resin from the tamarisk tree, and this edible substance does share some characteristics with the heavenly manna described in Exodus and Numbers-- it is yellowish in color, has a taste not unlike that of honey, and it melts when exposed to the heat of the sun. There are a couple of glaring problems with this theory, however; tamarisk trees aren't exactly abundant in the desert-- at least not abundant enough to sustain an entire population. Tamarisk resin is almost entirely sugar, so it lacks the nutritional value to sustain a human being for a significant amount of time. Also, it's not easily ground into a powder and baked into cakes.

Tamarisk tree in desert

Another leading theory is that manna is the crystallized, sugary substance secreted by many species of insects belonging to the coccoidea family. This substance, knows as "honeydew", would fit the physical description given by the Book of Numbers. Honeydew (the insect secretion, not the melon) can still be purchased in Middle Eastern markets as a delicacy. However, it lacks the proteins and fats necessary to support human life over an extended period of time.

This theory first gained traction in 1829 when German naturalists Wilhelm Hemprich and Christian Gottfried Ehrenburg traveled to the Sinai Mountains to study a species of mealybug known to locals as "mana scale", because it feeds on tamarisk trees. The insects secrete a sugary substance which many leading theologians insist is the manna described in the Old Testament.

Truffles and Star Jelly

There is also the theory that manna is, in actuality, a desert truffle. The word mana appears three times in the Koran, and is used to describe a variety of truffles in the terfeziaceae family. The problem with this explanation is that truffles don't melt in sunlight, and they look nothing at all like coriander seeds and don't taste like honey.

There are also a number of far less plausible theories, such as star jelly-- a whitish gelatinous substance that, according to Medieval legend, falls to earth during meteor showers and quickly evaporates (or melts) when exposed to sunlight. While some paranormal researchers claim that star jelly is extraterrestrial in origin, others have speculated that star jelly is nothing more than snail slime or the regurgitated entrails on amphibians after they have been eaten by predators. At any rate, it's not a substance one would care to eat, much less live on for forty years.

There is yet another theory about the true identity of heavenly manna, and proponents of this theory claim that manna is a variety of lichen-- a leafy, papery organism that commonly grows on rocks. These lightweight organisms detach themselves in wind storms and carry through the air for long distances. In some parts of the world, these lichen aerial falls have been known to form a deposit several inches thick.

Origins of the Lichen Theory

The lichen explanation was first put forth in 1921 by Oscar S. Heizer, the U.S. consul to Jerusalem. In one of his reports to Washington, Heizer described the aerial fall of manna that occurs in regions of Upper Mesopotamia and Kurdistan between the months of September and December. Heizer observed that this substance, immediately after falling to the ground, hardens and assumes the shape of a seed or grain. He also observed that its color was yellow on the outside but, when broken, the interior appeared white as snow.

The Kurdish tribesmen Heizer encountered in the Sinai Mountains gathered this substance early in the morning by spreading cloth sheets beneath trees where the manna had fallen and shaking the trunks. The Kurds then used a mortar and pestle to pulverize the substance into a flour, which was then used to make cakes. Heizer, however, had no idea what this edible product was.

Lichen growing on a rock

Heizer, who instantly saw the connection between the mysterious Kurdish manna and the Biblical manna, shared his theory with Consul Owens in Baghdad, who mailed a sample of the manna (along with one of the Kurdish cakes) to the Department of State in Washington for analysis, where the mystery ingredient was identified as a species of lichen.

The analyses performed by the Department of State revealed that the dried lichens contained 65% oxylate of lime and 25% starch and constituted a nutritious substance almost identical in chemical composition to the Arctic mosses upon which reindeer grazed. Historical records show that Kurdistan saw record "rainfalls" of lichen in 1824, 1828, 1841, 1846, 1863 and 1864.

In 1829, during the war between Persia and Russia, a severe famine impacted the lands southwest of the Caspian Sea until a windstorm covered the ground with a mysterious substance which the sheep devoured greedily, thereby suggesting to the starving soldiers that they may be able to eat it as well. Records shown that the native inhabitants ground this substance into flour and baked bread with it. In all likelihood, this "manna from heaven" was lichen. The lichen fall of 1828 was said to cover parts of Persia to a depth of six inches, while in the spring of 1841 a lichen fall near Lake Van in Asia Minor covered several square miles of ground to a depth of four inches.

Scientists who studied this phenomenon discovered that large aerial falls of lichen occurred not just in Kurdistan but also in the deserts of Armenia, Iraq, Iran, Arabia and part of northern Africa. In 1847 the commander of French troops in Algeria, General Jussuf, filed an official report claiming that his troops managed to fend of starvation by eating manna that fell to the ground.

Researchers who studied lichen falls in the early 20th century also found that, in some parts of southwest Asia, a single gatherer can collect between 12,000 to 20,000 pieces of lichen (approximately five to eight pounds) per day, which is considerably more than the amount of tamarisk resin or bug secretions (or star jelly, for that matter) that can be collected in a single day.

Although some theologians still cling to the alternate explanations, it would seem that the food which most likely nourished the Israelites during their forty years of wandering was indeed lichens.