Amethyst under polarized light Size:S: 36 x 28cm whilst a sullen America looks

whilst a sullen America looks on in the background

It was partly through works such as Colenso's

another customer receives gentler but discourteous treatment (right)

From Moses Pitt's The cry of the oppressed

View of Clare Market at the back of Portugal Row

Amethyst under polarized light Size:S: 36 x 28cm whilst a sullen America looksSixteen figures showing specimens of amethysts viewed under polarized light and exhibiting veined structures. Brewster notes in his text: 'The observations are the result of an immense variety of experiments, which accidental circumstances put it in my power to make upon this interesting mineral. Having access to whole bagfuls of amethystine pyramids from the Brazils, in the possession of Mr Alexander, lapidary in Edinburgh, I have examined some