Engineering Science and Materials Commons^™

Naturally occurring iron oxides were used since ancient times as ochre yellow and red pigments. It was only in the 18th century that artificially prepared Prussian blue was discovered. This discovery opened up a new field of chemistry - - cyano compounds.

Travelling scientists certainly have contributed to advancing knowledge by communicating their observations to others. Famous professors attract students from different countries to study in their institutions and the interaction among these students is of immense importance in the diffusion of knowledge. The invention of a process for the production of aluminum is an example.