A CONTRIBUTION TO THE STUDY OF AUSTRALITES. 
23 
same time as those found in the old river beds of the deep leads. 
They cannot thus be all contemporaneous, and if not contempo- 
raneous it is exceedingly difficult to understand why, if they are 
meteorites, one and the same small portion of the surface of the 
globe should be picked out each time for them to fall there only. 
The Bubble theory, as propounded by Mr. Dunn, in his 
own words is as follows : — 
These bodies represent the ' blebs” of obsidian bubbles. From the 
Eocene period to recent times, volcanoes were in active operation in Australia. 
In Victoria there was remarkable activity. During the outburst bubbles of 
glass of varying size were formed in the vents, and were carried up in the 
ascending gases to great heights. The bubbles were dispersed according to 
the direction of the wind, and in a few hours may have been carried for 
hundreds of miles. As they cooled, they would fall towards the earth, and 
either the act of coming in contact with the rocks, or the differences in tem- 
perature, would shatter the frail glass bubble, but the bleb which had formed 
at the bottom would remain. Chips would flv off on changes of temperature, 
just as they do from slag or unannealed glass, and this lias taken place. 
The buttons are the blebs of single bubbles, hence their symmetry. Around 
the edges of these the rim. when the glass bubbles break away, is often plainly 
visible. The examples contracted m the middle aie the blebs of double 
bubbles, hence their peculiar form, and round the edge of these the rim 
where the bubble was firmly joined to them is apparent in some cases. The 
stopper like bodies are blebs of a heavier glass, and around their edges the 
line where the bubbles joined them appears to have chipped oil. In the 
case of the remarkable hollow sphere, previously referred to, it is the bleb of 
a large glass bubble, and the step around the periphery marks the line where 
the bubble joined this hollow bleb. The dispersal in greater abundance 
over some tracts would indicate the prevalent direction of the wind, as well 
as the direction from which they were derived. These bubbles were un- 
doubtedly blown in volcanoes. Whether these volcanoes are the points of 
eruption so common in the southern portion of Victoria or not has yet to be 
determined.” 
I find that most persons believe, as I believed myself before 
trying it, that the bleb on a bubble is formed at its lowest point, 
and is in fact the scar that closes the site of its last attachment 
to its source. This is an entire mistake. Let anyone blow a 
soap bubble with a bleb on it, and he will see the bleb is on the 
very top. Tt is really the point first forming, while as the bubble 
floats off when complete the scar of its formation closes over, 
so as to be indistinguishable, and immediately the bleb, by its 
own weight, either turns the bubble over or slides down its side, 
so that it becomes the most dependent part. (Plate XIX, Fig. 2.) 
I find on again trying to blow a bubble with a bleb on it 
so that I can photograph it for this paper that it is by no means 
so easy as I thought, or as the late Mr. J. B. Allen appeared to 
find it. 
Possibly, as Mr. Dunn suggests, the outer loosely attached 
ring of the button form of Australite is formed of the superfluous 
glass running down from the. bubble and consolidating round 
the bleb, but the bleb itself would be formed, as in a soap bubble, 
at the top, becoming dependent later. This explains why 
