In the kingdom of Quito, the Tigua natives eat from choice, and without any ill consequences, a very fine clay mixed with sand. This clay, mixed with water, renders it milky. Large vessels filled with this mixture, called agua de llanka, water of clay, or leche de llanka, milk of clay, may be seen in most of their huts, where it serves as a beverage.
On the banks of the river Kamen-da-Maslo, there is produced a fossil, or an earthy substance, called in Russian kamennoye maslo, stone butter, which is eaten in various ways, as well by the Russians as the Tongousi, it is of a yellowish cream colour, and not unpleasant in taste, but it is forbidden as pernicious in its effects. This earthy matter is stated to be a fossil, or salt oozing out of rocks, in many parts of Siberia, but chiefly from those near the river Irtish and Yenissei. When it is exposed to the air in dry weather it hardens, but in wet weather it again becomes soft or liquid. The Russian hunters use it also as a bait. The animals scent it from afar, and are fond of the smell.
In Germany, the workmen employed in the quarries of sandstone at Kiffhauser, spread a fine clay upon their bread instead of butter, which they call steinbutter (stone butter). There is another substance, called bergbutter, or mountain butter, which is a saline substance produced by the decomposition of aluminous schists.
On the shores of a lake near Urania, in Sweden, is found a deposit, called by the peasants “mountain meal” (bergmehl) which they use, mixed up with flour, as an article of food. This deposit consists chiefly of fossil infusoria.
In Finland also, a similar kind of earth is mixed with bread stuff, as also in parts of Northern Germany in cases of scarcity or necessity. In Lapland also, this fossil farina has been found, and applied to a like use. The Tripoli or rotten stone of commerce is an infusorial earth of this description, composed of fossils of extraordinary minute dimensions.
A poor man, in the neighbourhood of Dejufors, Sweden, some years since, found an earth of this description, which had much the appearance of meal. The people being at that time in a state of privation, and living upon bark bread, this man took some home, mixed it with rye meal, baked it into bread, and found it palatable, hereupon there was a general run upon this earth, and some of it found its way to Stockholm. On analysis it was found to contain flint and feldspar, finely pulverized with lime, clay, oxide of iron, and some organic substance resembling animal matter, and yielding ammonia, and an oil.
Ehrenberg found that a hill in Bohemia was one mass of the siliceous fossil shells of these minute creatures, and that in a stratum fourteen feet in thickness, one cubic inch contained the remains of 41,000,000,000 of individuals.
These kind of deposits are continually accumulating, and producing important changes, in the bed of the Nile, at Dongola, and in the Elbe, at Cuxhaven, and even choking up some of the harbours in the Baltic Sea.
Dr. Trail analyzed a bergmehl from the North of Sweden, and found it to be composed of the minute shields of infusoria, about one thousandth of an inch in size, consisting chiefly of siliceous earth and alumina. A small quantity of this curious substance was found in County Down, Ireland, by Dr. Drummond, twenty years ago, while sinking a pit near Newcastle.
MM. Cloquet and Breschet ate experimentally as much as five ounces of a silvery green laminar talc. Their hunger was completely satisfied, and they felt no inconvenience from the use of a kind of food to which they had not been accustomed. In parts of the East, use is still made of the Bole earths of Lemnos, which are clay mixed with oxide of iron.