Published in Transactions of the South African Philosophical Society, in 1890, in volume 8, issue 1, pages 1-11

Published in Transactions of the South African Philosophical Society, in 1890, in volume 8, issue 1, pages 12-15

Published in Transactions of the South African Philosophical Society, in 1890, in volume 8, issue 1, pages 23

Published in Transactions of the South African Philosophical Society, in 1890, in volume 8, issue 1, pages 24-32

Published in Transactions of the South African Philosophical Society, in 1890, in volume 8, issue 1, pages 35-39

Published in Transactions of the South African Philosophical Society, in 1890, in volume 8, issue 1, pages 40-49

Published in Transactions of the South African Philosophical Society, in 1890, in volume 8, issue 1, pages 50-51

Published in Transactions of the South African Philosophical Society, in 1890, in volume 8, issue 1, pages 52-62

Published in Transactions of the South African Philosophical Society, in 1890, in volume 8, issue 1, pages 63-76

Published in Transactions of the South African Philosophical Society, in 1890, in volume 8, issue 1, pages 77-78

Published in Transactions of the South African Philosophical Society, in 1890, in volume 8, issue 2, pages 84-85

Published in Transactions of the South African Philosophical Society, in 1890, in volume 8, issue 2, pages 86-92

Published in Transactions of the South African Philosophical Society, in 1890, in volume 8, issue 2, pages 93-109

Published in Transactions of the South African Philosophical Society, in 1890, in volume 8, issue 2, pages 110-112

Published in Transactions of the South African Philosophical Society, in 1890, in volume 8, issue 2, pages 113-118