44 Proceedliyj'i of the Ro)jal Societij of Victoria. 



■carried immense distances from its source. On the other hand, 

 some of the obsidianites weigh an ounce and more, and heavier 

 ejectamenta such as these would only be subject to a compara- 

 tively slight divergence from their original flight. 



It is quite evident, from their manner of distribution, that 

 considered as volcanic terrestrial products, obsidianites could not 

 have originated from a single eruptive centre. Neither are we 

 much enlightened by assu)ning that they were ejected from a 

 number of volcanic points situated within a reasonable distance 

 of the places in which they were found, because many of the 

 occurrences are remote from the nearest points of possible 

 eruption, and we cannot satisfactorily account for their trans- 

 portation ; and is it possible to believe that such extensive 

 denudation took place as to remove all concomitants of a wide- 

 spread volcanic outburst, and at the same time leave these 

 objects, some of which are in a most perfect state, as the sole 

 representatives. Naturally these small objects would have yielded 

 much more rapidly to decomposing influences than the extensive 

 contemporaneous lava flow, and therefore have been the first to 

 disappear. At Mount Elephant and Mount Eccles in our colony 

 we have them actually occurring within an extinct volcanic area, 

 and it might be thought that they originated from these points. 

 As far as is known all the most recently ejected lavas of this 

 part are basic, and in several parts vesicular bombs abound, l)ut 

 they difi'er totally in every respect from obsidianites, which we 

 have already seen ;ire acid. Now, as far as experience goes, 

 nowhere within that locality, or indeed within the colony, have 

 acid lavas been found. Some of the ol)sidianites are quite perfect 

 in every respect, showing not a trace of decomposition, and are 

 found lying upon the basaltic lavas now undergoing decomposition, 

 and which are the products of our most recent volcanoes. Making 

 due allowance for their difference of composition, which enables 

 obsidianites to resist the attacks of decomposition longer than 

 the bombs of a basic nature, it would be strange, if they are 

 contemporaneous, that they are so perfectly preserved. And t<> 

 assume contemporaneity we must believe that basic lavas anil 

 acid bombs were ejected at one and the same time, a state oi 

 things most highly improbable. If they really owe their origin 

 to an acidic volcanic outl)urst, and by some means unknown to us 



