Figure 2 The use of precious substances through time.

Again, methods for displaying precious substances were of an elementary character.

It remains to consider the third phase in the history of precious substances.

As with other precious substances, ivory was used far beyond the areas where it occurred in nature.

It was this precious substance which brought life to the machines.

He reached out and captured some of the precious substance.

It is the scarcest, most precious substance in our world.

It seemed to help, yet the doctors had very little of the precious substance.

Water-perhaps the most precious substance in the System, for the purposes of man.

Iraq started producing this precious substance before the war, but never got close to making enough for a bomb.