Art. LII.—On the Distillation Products of the Blackball Coal.
[Read before the Philosophical Institute of Canterbury, 2nd November, 1898.]
The following experiment was carried out with the object of testing the results re distribution of sulphur arrived at in Part I.*:—
The coal was placed in a bent bulb-tube of hard glass (a), connected in series with a Würtz flask (b), a U-tube (c) filled with dry cotton-wool, three small wash-bottles (d1, d2, d3) containing an ammoniacal silver nitrate solution, and an aspirator. The aspirator was arranged so as to just counterbalance the liquid columns in the wash-bottles. The tube containing the coal was hooded with asbestos millboard, and very gradually brought up to a full red heat. At the end of
[Footnote] * Trans. N.Z. Inst., vol. xxx., p. 489.
the experiment the neck of the tube retort was sprung off above the bulb which contained the coke;
[The section below cannot be correctly rendered as it contains complex formatting. See the image of the page for a more accurate rendering.]
|Tube (a), empty||52.801||∴ Coal||10.058|
|Tube (a), + coal||62.859|
|Flask (b), empty||43.560||∴ Tar, &c.||3.012|
|Flask (b), + tar, &c.||46.572|
|Tube (c), empty||27.580||∴ Tar, &c.||0.006|
|Tube (c), + tar, &c.||27.586|
|Neck of tube (a) + tar||18.604||∴ Tar, &c. 0.139|
|Neck of tube (a) cleaned||18.465|
|∴ Total liquid distillate||3.157|
|Bulb of (a) + coke||39.715||∴ 5.379|
That is, coal gave 31.38 per cent. of tar and water, 53.48 per cent. of coke, and 15.14 per-cent. of gas and loss; as compared with 29.25 per cent. of tar and water, 57.25 per cent. of coke, and 13–50 per cent. of gas and loss of former series.
The silver-sulphide from the three wash-bottles gave 1.347 gr. of metallic silver, equivalent to 0.2126gr. of sulphuretted hydrogen, or 0.2001 gr. of sulphur.
The coal contained 4.63 per cent. of sulphur, of which (vide Part I.) 50.5 per cent., or 0.233 grammes, should have been expelled in the gaseous distillate.
That 83.8 per cent. of this calculated amount was actually accounted for as sulphuretted hydrogen is a further justification of the conclusions arrived at in Part I.