Main part of set, 9 of 12 specimen tubes, containing samples of solutions for spectroscopic comparison purposes, in small red leather covered case, c.1870. 1) Nitrate of didymium 2) Hofman's violet 3) Cobalt in calcium 4) Nitrophenic acid 5) Cyanide of cobalt 6) sulphate of indigo 7) Cobalt in alcohol 8) Chromic sulphate 9) Oxylate of chromium and soda. each sample in a sealed glass phial (see note). Main part of set 1865-1875
Ten sealed glass phials containing coloured liquids for use with a spectroscope to demonstrate adsorption spectra of different materials, in a fitted box for 14 samples, estimated date 1875-1924. Includes three samples labelled Didymium, a substance later found not to exist. (one phial missing on receipt and three containing uranium compounds sent for disposal before accession.) Ten sealed glass phials containing coloured liquids for use with a spectroscope 1875-1924 (estimated)