Originally, iron blue was potassium ferriferrocyanide, FeK[Fe(CN)₆], but it was found that potassium could be replaced with sodium or ammonium at lower cost and no sacrifice in properties.

He is unable to select his crude, and often has to be satisfied with a worse residuum; nor is he in a position to dispose of his goudron as the latter, and for all these reasons, such a refinery is compelled to secure as high a ...

Lesedi was a sangoma, you know. I think she tried to put a curse on me because I was spying on her. But I wasn't really spying, I just thought that she was nice and wanted her to be my friend and then I saw the mask and I didn't anymore.

to exercise troops or horses;  to exercise one's brain with a puzzle