203 



The positions of 1 and 2 I obtained by careful micrometer 

 measurement, the other numbered lines I estimated. 



The spectra I have given for comparison (atmospheric and 

 calcium) are the only ones I can find mapped in Roscoe's 

 work that can at all compare with the " glow " spectrum ; 

 that of calcium, especially BunserCs, appearing to me to have 

 the most resemblance. 



In recording these observations I do so in the position 

 of a witness, and not that of a judge, hoping that the evidence 

 I have to offer may, in connection with that contributed by 

 others, help in some measure to elucidate the mystery of the 

 phenomenon that has excited so much interest. I dare not 

 venture to offer an opinion upon these observations, only, I 

 would remark, that the idea of calcium vapour being in the 

 air at this time is perhaps not very absurd, considering the 

 vast quantity of limestone that must have been in contact 

 with volcanic heat. 



I am not yet prepared to offer a definite opinion upon the 

 deposit which 1 collected from the January rains. I have 

 submitted it to a partial examination in the microscope, 

 and found the heavier portion, obtained by precipitation in 

 water, to consist, apparently, chiefly of silicious particles, 

 intermixed with insect exuviae, etc. ; also a few particles of 

 magnetic substance, somewhat pear-shaped, evincing, in 

 proximity of a magnet, decided polarity. The lighter 

 washing exhibited, microscopically, a marked resemblance to 

 a specimen of volcanic dust with which I compared it. 



This volcanic dust specimen was given me by Mr. Dean, 

 sen., of Launcestou, who obtained it, I believe, from the 

 captain of the ship upon which it fell in the vicinity of 

 Sunda. 



EEFEEENCES TO BAEOISl CONSTANTIN VON 

 ETTINGSHAUSEN'S RECENT OBSERVATIONS 

 ON THE TERTIARY FLORA OF AUSTRALIA, 



By Baeon Feed. Von Muellee, KC.M.G., M.D., F.R.S., 



F.G.S., Etc. 

 [Bead Axml 8, 1884.] 



The 47th volume of the Imperial Academy of Science, 

 Vienna, issued this year, contains an important essay on 

 tertiary vegetable fossils of Australia, the results of original 



