Chemistry Naturewalk

Sodium silicate, "silica".  A dessicent used to absorb moisture from the air.  Will dissolve in an strongly alkaline sodium hydroxide solution yielding "waterglass"  sodium silicate solution.
 
Tempered safety glass
 
oxidation and reduction zones in a propane flame

 
India ink. A suspension of very finely divided carbon. Often derived from "lampblack" the soot collected on a surface from a poorly burning flame. India ink is used in the medical setting to detect cryptococcus (a fungal organism responsible for a form of meningitis) . A drop of ink is mixed with the suspect fluid and the clear capsule of the cryptococcus is seen against the black background of the ink.
 

 
Uranium glass marbles
 
Sodium silicate