334 PROCEEDINGS OF SECTION B. 
No. 9.—ON “RED RAIN” DUST. 
By Tuos. Sree, F.L.S., F.C.8. 
(Read Monday, January 10, 1898.) 
From time to time records of the fall of dust, either alone or 
accompanied by rain, are received from various parts of the 
colonies, in common with the rest of the world. 
Although it is extremely probable that in the great bulk of 
these cases the dust is merely of terrestrial origin, it is interesting 
when positive facts regarding the source of the material can 
be ascertained. On December 27th, 1896, there occurred over 
Melbourne and a considerable area of Victoria an unusually 
heavy fall of dust of a red colour which was carried down by 
accompanying rain. 
Various observers have made known the results of microscopical 
examination of dust from this shower ; but, so far as I am aware, 
no chemical analysis of it has been published. 
By means of a large paper-filter, my friend, Mr. W. E. 
Appleby, who was then resident at Moonee Ponds, near Mel- 
bourne, collected a very clean sample of the dust, which he kindly 
handed to me for examination. The sample was sufficient to 
enable me to determine the amounts of the leading constituents 
with a fair degree of accuracy. The following are the figures of 
analysis :— 
Dried at 110° C. 
Organic matter,* &c. (loss on ignition) Ae 10°70 
Sand, insoluble and undetermined ... oe 66:23 
Soluble silica ... ine sts oe a “15 
Ferric oxide... oe ar soe Rie 4-68 
Ferrous oxide ... cee ee ir oe 50 
Alumina ee ome a oe ae 15:16 
Lime ... Be ve aa on hs 1:36 
Sulphuric anhydride ... as ail ti 62 
100-00 
The above may be considered as a characteristic example of 
ordinary surface soil such as is derived from the weathering of 
volcanic rocks. In appearance and composition it agrees closely 
with volcanic soils from such widely separated localities as 
Northern Queensland, New South Wales, and Fiji, which I have 
examined. 
* Containing nitrogen : ai oF ae oO. 
Moisture in air-dried sample .. 3¢ ac .. 6:08 
