The Remarkable Sunsets. 



M. \V. B e ij e r i n c k and J. v a n Dam. 

 Nature, London, Vol. 29, 1884, p. 175. 



We have received the tollovving Communications: — 

 Early in the morning, on December 13, between four and five o'clock, 

 a violent tempest from the north-west arose. The temperature in the course of 

 the morning was rather low, viz. 4" C, and, especially between six and seven, the 

 wind was accompanied by showers of rain, intermingled with hail. This rain was 

 of a peculiar nature, every drop, after having dried up, leaving behind a slight 

 sediment of grayish coloured substance. This was most distinctly to be seen on 

 the panes of windows turned towards the west or the north-west; the spots with 

 which these panes were dotted did not leave the least doubt about their having 

 been caused by the fallen rain. 



The streamlets of rain, having evaporated, left on the whole surface of the 

 windows the said grayish matter behind, so that there can be no doubt but the 

 rain itself had conveyed from the upper air the above dust. 



The magnificent »cloud-glow« which, on several previous evenings, had also 

 been observed hereabouts, and which has been attributed by meteorologists — with 

 good right, no doubt— to the volcanic ashes due to the catastrophe of Java, made 

 us suppose that the substance observed by us on the windows could not but be 

 of the same origin. We took it for granted that whirlwinds, when the storm set 

 in, had brought the dust down to the lower regions of the atmosphere, where it 

 mingled with the falling rain. Consequently we proceeded to examine microscopi- 

 cally the sediment, in order to compare it with original ash from Krakatoa, which 

 had been sent to the Agricultural Laboratory at Wageningen to have its value as 

 plant-food ascertained. The result of this examination was that both the sediment 

 and the volcanic ash contained (i) small, transparent, glassy particles, (2) brownish, 

 half transparent, somewhat filamentous, little staves, and (3) jet black, sharp-edged, 

 small grains resembling augite. The average size of the particles observed in the 

 sediment was of course much smaller than that of the constituents of the ash. 

 These observations fortify us in our supposition, expressed above, that the ashes 

 of Krakatoa have come down in Holland. 



