1868. ] Amber ; its Origin and History. 169 
“Green Sand” are cemented by hydrated oxide of iron into a coarse 
sandstone, which is important on account of its containing remains 
of numerous animals, which have not been preserved in the loose 
sand. Under the “Green Sand” lies a deposit, consisting of finer 
quartz-grains and a larger quantity of Glauconite, besides containing 
clay and Mica, which increase in quantity the deeper the deposit is 
penetrated. The Glauconite gives it, in the dry~state, a greyish- 
green colour, which becomes nearly black when the rock is moist. 
Generally, also, the following beds can be distinguished in this 
deposit. The uppermost, from 5 to 8 feet thick, is called a “Quick- 
sand” (Fig. III. b), because it contains a large quantity of water, 
which has been arrested in its descent by the underlying clayey 
stratum; next follows the so-called “Blue Earth,” or “Amber- 
earth,’ which is from 3 to 4 feet thick, and more firm, dry, 
fine-grained, and argillaceous than the “Quicksand.” The still 
more deeply seated deposit is called the “ Wilde Erde,” because it 
contains no Amber. It has been explored only here and there to 
the depth of from 10 to 18 feet; and generally there has been no 
inducement to penetrate farther. It is also unknown how deep 
this formation continues and what underlies it. 
The Amber occupies only a narrow zone in the whole formation ; 
in this indeed, it occurs abundantly, but 1s not equally distributed. 
For each square foot of the surface of the bed, that is, one cubic 
foot of sand, from 31b. to 1 lb. of Amber may be reckoned as about 
the average. ‘The pieces are of various sizes, those weighing as 
much as half-a-pound being seldom found ; and larger lumps of one 
or more pounds weight are extremely rare. Their surfaces are dull 
and worn, and their edges and angles are also somewhat rounded, 
but not to a sufficient extent to obliterate the various forms which 
they originally received as the liquid resin of a tree, such as pins, 
drops, and plates, which were formed between the bark and the 
wood, or between the yearly rings of growth of the stem. Fre- 
quently, also, fine impressions of the parts of the plants which 
produced them can be distinguished on their surfaces. It follows, 
therefore, that the pieces of Amber were for some time, but not for 
very long, rolled about by the water previous to their deposition. 
With the Amber also occurs fossil wood, but generally only in 
small pieces, which were probably half-decayed when they were 
deposited. The complete stem ofa tree has never yet been found in 
the Amber-earth, and solid pieces of a foot or more in length are 
very rare. Such pieces of wood as still have Amber attached to 
them are of especial interest; and there are even some so completely 
penetrated with Amber-resin that they appear to consist not so 
much of wood-fibres as of Amber-filaments. In the “ Amber-earth” 
and in the lower part of the “Quicksand,” there also occur pieces 
of compact clay and marl, which contain numerous fossils, the same 
