Here is a medicament much appreciated by our Roman ancestors, an extraction of homegrown efflorescence.

This variation is manifested in the ratio of carbon dioxide in air, the rates of heat and moisture change, salt-efflorescence and salt-subefflorescence.

Paradoxically, it was also the century that witnessed, in many parts of the world, the triumph of non-violence, the end of colonial rule and the efflorescence of civil society.