When working, it splits light into its component colours, to reveal information about the chemical content, temperature and motion of planets, comets, stars, interstellar gas and galaxies.

BBC: Brute force helps Hubble renewal

There is no guarantee against unscrupulous inspectors clandestinely collecting samples and conducting off-site analysis to glean information on the chemical content of American products and the processes involved in making them.

CENTERFORSECURITYPOLICY: Chemical Weapons: Say No to This Troubled Treaty

FracFocus was created to address a very specific issue that had been raised by environmental groups: Several years ago, there was supposedly a hue and cry from landowners wanting to know the chemical content of the frac fluids that were going down oil and gas wells on their land or on adjacent lands.

FORBES: Harvard's Frack Disclosure Study Earns an 'F'

Conceding the point, Dow has cut back production of chemicals in North America and is content, in effect, to collect a fee for showing the Arabs how to run a chemical plant.

FORBES: Magazine Article

The chemical composition of paints has been examined, and some paints have even been radioactively dated (it is the lead content that is key here).

ECONOMIST: Finding forgeries: Different strokes | The