XXXVI. Notes on the geographical distribution of organic remains contained in the oolitic series of the Great London and Paris Basin, and in the same series of the South of France

Henry T. De la Beche
1830 The Philosophical Magazine  
produced by the rising of the aqueous vapours has ceased, throw in another portion, and so on; and keep the crucible, when the whole mixture has been introduced, for about one hour in a moderate red glowing heat (if the heat is too great, it destroys the eolour); when cold, pour water into theerucible, and separate by means of it the brown residue of sulphur mixed with the ultramarine. A superabundance of sulphur may be expelled by a moderate heating. If the colouring is not of an equal
more » ... of an equal intensity, the most fiery ultramarine (and this is a very important circumstance) may be obtained by washing, and separating it from those parts which are less coloured. From the component parts of the ultramarine as given by the analysis, it cannot be forxned, without a medium. Thus this eotour is nothing else than a silicate of soda dyed with sulphuret of sodium. " The natural ultramarine contains a not inconsiderable portion of potash and sulphuric acid ; and it is very probable that the artificial production here mentioned may beusefully varied, but this can only be discovered by experiment." XXXVI.
doi:10.1080/14786443008675283 fatcat:t2gq5aelmnamtasggiqnssssy4