The Roman author, Elder Pliny, explains the invention
of glass in his writings Natural History. "A trading ship
carrying nitrum anchored (off the coast of modern Lebanon); its crew went
ashore to prepare their dinner. Finding no stones on the beach with
which to prop their cooking pots over the fire the sailors used lumps of
nitrum from their ship to support their cookware. When these became
heated, they combined with the sand from the beach to form a 'strange liquid
that flowed in streams; and this, it is said, was the origin of glass.'"1
The basic science behind this phenomenon described by Pliny is the mixture
of silica (pulverized quartz or quartz sand), nitrum (basically soda) and
lime (most likely also contained in the beach sand).2
Early Celtic glass was most likely prepared in this simple manner.
The knowledge behind the combination of ingredients for the production
of glass did not however, occur quite as haphazardly as Pliny suggests.
It originated farther east than the shores of Lebanon, in the ancient country
of Mesopotamia during the third millennium BC, where the recipe was written
on clay tablets in cuneiform script.3 The knowledge of
glass making made its way through history and was probably passed on by
way of Phoenician traders to early continental Celtic tribes. Either
creating their own glass from raw materials, importing raw glass from Greek
city states, or melting down imported glass trading vessels (perhaps those
that carried wine from the south), the Celts began to incorporate this
new medium into their artistic repertoire. 
The difficulty in fashioning glass artifacts, producing
raw glass or the expense of importing raw glass lead to a very centralized
craft production and distribution. "Evidence suggest that the manufacture
of glass objects was amongst the most centralized and specialized of any
of the branches of craft production in the late La Téne period."4
Localized glass production meant that larger oppida would contain a majority
of glass artifacts. Major glass working oppida during the La Téne
period were: Stradonice, Staré Hradisko and Manching. Peak
glass production occurred during the late La Téne C2 and D periods.5
Most glass artifacts dating to the Celtic La Téne
period were core formed or rod formed. Core formed objects were made
by molding molten glass around a removable core or center. This core
usually consisted of a combination of dung and clay mixed with water, so
that it may be shaped and attached to some type of metal rod. The
core was then covered with glass and shaped in a kiln using the metal rod
and other tools. Patterns and colors were added to the artifact using
the rod forming method or a variation thereof. This method was most
commonly used in the production of glass beads. In the rod forming
technique, a glob of molten glass is attached to the end of a rod.
The glass is then heated in a kiln until it is malleable. At this
stage the glass can be shaped into a bead or other object. To apply
patterns or other colors to either rod formed or core formed artifacts,
glass of another color is attached to the rod, heated and then drawn out
and around the object (in the case of spirals for example) or pressed onto
the object (as in the case of circles or dots). The entire artifact
can be reheated and reworked numerous times to create complex patterns
and combinations of colors. [This section on glass forming techniques
was demonstrated and developed by Bill Gudenrath in Harry Abrams: Glass
5,000 Years pgs. 214-6]
Common Celtic patterns employed in the creation
of glass artifacts are for the most part very simple and geometric.
Inclusion of these on glass objects may have been believed to enhance the
properties of the glass itself. These patterns are most apparent
in glass beads. One of the most widely used is the spiral pattern.
Since prehistoric times spirals have been associated with death.
They may have also been used as solar symbols. Almost, if not as
common as spirals are patterns consisting of concentric circles.
These resemble eyes and may have been used as protection against misfortune;
as in the 'evil eye.' Triskels, s-scrolls, running-dog patterns,
and chevrons (all indicators of the La Téne style) are also quite
commonly found among Celtic glass artifacts of the time. 
Glass, as a material, had special meaning
for Celtic tribes. Early on this new product was of great value not
only because of its scarcity but because it resembled semi-precious stones.
Most scholars agree that the wide variety of colors found in glass
are the result of producers attempts to copy those stones. This new
glass material also resembled amber, which traditionally had 'magnetic
power.'6 The similarities among semi-precious stones,
amber and glass and well as the scarcity factor endowed glass with 'magical'
properties for Celtic tribes. The shaping of glass and the addition
of patterns enhance these qualities; thus glass begins to be incorporated
and used for adornments in Celtic societies.
In the preparation of this small catalogue the portrayal
of a variety of uses for Celtic glass artifacts is attempted. Included
in the catalogue are entries for beads, bracelets, gaming pieces, cult
objects, and necklaces. Glass beads are the most common surviving
of the artifacts. Their size and construction account for much of
this survival. During the Roman period some beads were used for votive
purposes at sacred shrines, wells and temples. Of note here, the temples
were of both Roman and pre Roman Celtic types.7 A major
use for beads was in the crafting of brooches. Often brooches were
worn in pairs on the shoulder region and connected with strings of beads.
A string of 176 beads found on a site in Essex, England was used to connect
two two gilt bronze saucer brooches.8 Several other brooches
also from the site were found to be connected with strings of beads.
The discovery of glass within a grave context seems
to be quite a factor in determining the nature of who is buried in the
tumulus or grave. More often than not, skeletal remains dating back
to this period are completely destroyed by acidic soil; all that is left
is a silhouette of noticeable chemical compounds left by the body.
Usually when glass is found at these or any site where the sex of the skeleton
is unknown, the prognosis is female. M.U. and W.T. Jones write "Beads
as well as brooches are the principal indication of a woman's grave," in
reference to their analysis of excavations at Mucking, Essex, England.9
Glass jewelry played a part in the identification of the Rheinheim
"Princess" tumulus in southern Germany. "As the body had been buried
with 13 glass beads the opinion has been that the deceased was a girl,"
states Tove Hjørungdal in A Gender Critical Perspective.10
1. Abrams (1991) pg. 21
2. Abrams (1991) pg. 8
3. Abrams (1991) pg. 8
4. Gebhard I pg. 112
5. Cumberpatch pg. 67
6. Guido (1978) pg. 22
7. Guido (1978) pg. 38
8. Jones (1975) pg. 182
9. Jones (1975)pg. 183
10. Hjørungdal pg. 23
List of Pictures and Credits:
Photographs of "Raw Glass" page 1: plate 61, DerGlasschmuck
Aus Dem Oppidum Von Manching.
Diagram of Necklace on "Bead" page 2: plate VII, Corpus of
Celtic Finds in Hungary.
"Glass Dog" page 3: Image #216373, Celtic Art & Cultures
(website)
"Princess" Rheinheim Necklace page 4: _____? (website)
Fragments of "Armlets/Bracelets" page 5: plate 6 pc. 101, plate
39 pcs. 506a and 506b, DerGlasschmuck Aus Dem Oppidum
Von Manching.
Welwyn "Gaming Pieces" page 6: plate 71, Glass 5,000 Years.
Bibliography:
Guido, Margaret. (1978). Prehistoric and Roman Glass Beads
in Britain and Ireland.
Abrams, Harry N. (1991). Glass 5,000 Years.
Cumberpatch, __________? pgs. 65-8.
Cunliffe, Barry. (1978). Hengistbury Head.
Gebhard, Rupert. (I) 'The Celtic Oppidum of Manching and its exchange
system,' Iron Age in WesternEurope, pgs. 110-2.
Gebhard, Rupert. (II) (1989). DerGlasschmuck Aus Dem Oppidum
Von Manching.
Hjørungdal, Tove. 'Early Iron age in Western Europe: A
gender critical perspective,' Iron Age in WesternEurope, pg.
23.
Jones, M.U. and W.T. (1975). 'The crop-mark sites at Mucking,
Essex, England,' Recent archaeological excavations in
Europe, pgs. 133-187.
Note for Dorothy:
I haven't had a chance to put in the bibliography
page here at the end of the essay. I was also wondering if you had
any suggestions on how to wrap this up --it feels fairly disjointed when
I read it back to myself. There are also a few loose ends to be tied
up in a couple of the catalogue entries, i.e. crediting the pictures as
well as a few quotes. I'll try to include some in-line text links
to the ages from this main essay, but. . . Hopefully I'll have all that
done by Wednesday for our get-together.
Thanks,
Jason