Many of the objects we see in galleries
undergo conservation and scientific
examination. Here is a glossary of terms
the British Museum's conservators and
scientists use behind the scenes. 
Episode one: Scientific research.
The British Museum has a department with a team
dedicated to scientific research. Their
task is to find out what objects are
made of where they're from and where and
how th ey were constructed.
Gas chromatography mass spectrometry is used
to identify resins fats and waxes. A
minute sample is dissolved and injected
into the chromatograph which is an oven
containing a polymer coated column. The
samples move through a stream of helium
gas and emerge into a detector which
produces a chromatogram. The detector
here is a mass spectrometer which splits
the chemical compounds into ions
recorded as a mass spectrum to identify
mixtures of materials. For example
beeswax and pine resin.
Radiography uses x-rays a special type of invisible light 
which can pass all the way through
objects. By using x-rays we can look
inside valuable and delicate objects
without opening or damaging them, so we
can answer questions about their
condition, how they were made, or if
anything is hidden inside.
Scanning electron microscopy is used to study
objects at magnifications up to several
thousand times which is much higher than
with light microscopes. The object is
viewed by scanning a beam of electrons
onto the surface and collecting the
signals. These are used to produce a
clear image which appears in shades of
grey for surfaces as small as one
nanometer.
X-ray diffraction is used to identify
material with a crystal structure such
as stone or minerals. It can also be used
to identify corrosion. X-rays are fired
into an extremely small sample, bounce
inside it, then reflects out and are
analysed. The speed and the angle at
which X rays are bounced back or
refracted helps to tell us the object's
composition.
X-ray fluorescence spectrometry or XRF identifies the
chemical elements in objects. X-rays are
fired into a sample causing atoms to
emit fluorescent x-rays which work as a
fingerprint for the elements. Portable
XRF can be used in situ for objects that can't be brought into the laboratories,
or to detect original pigment on objects in galleries
before any conservation procedures are
carried out. Scientists at the Museum use
many other research techniques listed in
the Science and Conservation glossary
you can find out more by visiting the
World History Lab website. www.worldhistorylab.britishmuseum.org
To understand more about work at the museum see:
Episode Two: Conservation
