Second referee's report by Henry Clifton Sorby, on a paper 'The structural arrangement of the mineral matters in sedimentary and crystalline pearls' by George Harley Recommended for publication in the Proceedings of the Royal Society of London. Suggests that the paper would be improved by studying pearls under polarised light. Subject: Chemistry, Geology [Published in the 'Proceedings of the Royal Society of London', 1889] nd [1889]