246 A. LIVERSIDGE. 



As the result of the examination, I think that part of 

 the dust is of meteoric origin, but there is also no doubt 

 that the main bulk of it is from terrestrial sources. I do 

 not think it is of volcanic origin, since it does not present 

 the characters of a volcanic ash; there are but few traces 

 of augite or other crystals such as we might reasonably 

 expect to be present in a windborne volcanic dust, further 

 the large proportion of combustible matter present is 

 against this idea. Most of it has doubtless been derived 

 from the deposits left by dried up fresh water pools, lakes 

 or watercourses, for with the exception of the fragments 

 of shells, the dust is quite unlike a sea shore deposit; the 

 shells and diatoms may be either of fresh water or marine 

 origin, the sponge spicules, however, point to the latter 

 source, but these together with other portions of the dust 

 may not have been deposited at the same time. More 

 light would probably be thrown upon the question could 

 specimens of the mud which fell at the same time on board 

 ships off the coast be submitted to an examination. 



I do not suppose that much if any of the combustible 

 matter is of meteoric origin although considerable amounts 

 of carbonaceous and bituminous substances have been met 

 with in several meteorites, e.g. the Bokkeveld, Kaba and 

 other meteorites ; the nickel-iron meteorites found at 

 Bingera, N.S.W. and elsewhere, contain carbon; in fact 

 carbon is commonly present in metallic meteorites. But 

 I think the metallic portion is of meteoric origin and per- 

 haps part of the earthy matter also. The probability of 

 the metallic portion being of cosmic or meteoric origin is 

 borne out by the peculiar appearance of the iron, its 

 imperfect malleability, resembling in these respects cer- 

 tain other irons of undoubted meteoric origin ; by the 

 presence of cobalt and the probable presence of nickel; 

 copper was found in the hydrochloric acid solution of the 



