Ferdinand von Mueller

1

Letter not found. The text given here is from 'West Australian asphalte', Perth gazette and West Australian times, 26 July 1867, p. 3 (B67.07.04). M's letter is introduced by 'About three months since the Colonial Secretary transmitted to Dr. Mueller, Melbourne, a specimen of Bitumen gathered by him from Rocks in the Warren River country, where it is to be found abundantly. By the mail which arrived last week, Mr. Barlee received, in reply from Dr. Mueller, the following most interesting communication:—‘.

The bituminous substance collected south of Swan River

2

WA.

and submited to my examination, is pliable under slight force at ordinary temperatures, and when kneaded it is susceptible of very good impressions. Bisulphide of carbon dissolves it easily without application of heat; in kerosene and oil of turpentine, and Eucalyptus oil, it dissolves slowly while cold, but readily under the influence of moderate heat. It is unacted on either by alcohol or methylated spirit; ether effects it but slightly.

When submitted to destructive distillation a pale oil of a somewhat brownish red passed over; the later portion of this oil shows an inclination to congeal; it is lighter than water. At the ordinary temperature the oil shews no tendency to inflame on applying light, but does so readily at a raised heat, burning then with a brilliant but smoky flame. The quantity of this resinous substance at disposal for examination was too small to admit of fractional distillation, but possibly the portion first distilling over might be employed for illumination, while the latter portion would serve for lubricating purposes.

By melting together one part of this substance and three parts of shellac a very good black sealing wax can be obtained, to which a small admixture of gum resin of

Xanthorrœa

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would give also fragrance, the strong natural odor of the resin vanishing by the heating process. This new kind of sealing wax (of which a sample is transmitted) possesses great brilliancy, and taking well marked impressions; it would be remarkably cheap as it would save the use of Venetian turpentine and ivory black, of which jointly 40-100ths are required for good sealing wax.

When dissolved in turpentine the varnish thus formed gives a brilliant black lustre to wood. The solution can also be used for the manufacture of waterproof cloth, a small sample of which is forwarded. The excellence of this water-tight clothing would consist more particularly in cheapness, pureness of color, and in its elasticity, this last quality being so great that even at a heat somewhat exceeding the boiling point it does not become sticky or adherent.

Tests upon a large scale would show whether this asphalte could be used for paving purposes instead of the ordinary bitumen so used.

The medical properties of this Australian bitumen would probably prove kindred to those of examined allied substances.