From the bases of groups V. and VI. these are separated by hydrogen sulphide, from iron in alloys, ores, etc., and in general the iron is separated as basic acetate, and the manganese afterward precipitated with chlorine. Bromine is generally used in place of chlorine, the use of which chemists claim as troublesome; but in a number of examinations I have found it to yield more satisfactory results than bromine, which is much more expensive.
From the acids in insoluble and a few other compounds, chromic, arsenic, and arsenious acids, by fusion with carbonate of soda in presence of carbonic acid gas; borate of manganese is readily decomposed when the boracic acid is to be determined by boiling with solution of potassa, dissolving the residue in hydrochloric acid and precipitating the manganese as binoxide. This boiling, however, is seldom needed, as the borate is soluble in HCl.
From phosphoric acid I always use Girard's method of treatment with tin, using it rasped, and it yields much more accurate results with but little manipulation. When the other acids mentioned above are present in the compound, we treat it as directed there.
From silicic acid, by evaporation with hydrochloric acid.
From sulphur or iodine, by decomposing with sulphuric acid and separating this with baryta chloride.
RESEARCHES ON ANIMALS CONTAINING CHLOROPHYL.
[Footnote: Abstract of a paper "On the Nature and Functions of the 'Yellow Cells' of Radiolarians and Coelenterates," read to the Royal Society of Edinburgh, on January 14, 1882, and published by permission of the Council.--Nature.]
It is now nearly forty years since the presence of chlorophyl in certain species of planarian worms was recognized by Schultze. Later observers concluded that the green color of certain infusorians, of the common fresh water hydra and of the fresh water sponge, was due to the same pigment, but little more attention was paid to the subject until 1870, when Ray Lankester applied the spectroscope to its investigation. He thus considerably extended the list of chlorophyl containing animals, and his results are summarized in Sachs' Botany (Eng. ed.). His list includes, besides the animals already mentioned, two species of Radiolarians, the common green sea anemone (Anthea cereus, var. Smaragdina), the remarkable Gephyrean, Bonellia viridis, a Polychæte worm, Chætoperus, and even a Crustacean, Idotea viridis.