BLACK RAIN. 253 



loped the whole city, which was so dense that 

 the inhabitants were compelled to use artificial 

 lights. The appearance was grand in the ex- 

 treme. About three o'clock a slight shock of an 

 earthquake was felt, accompanied with a noise 

 like the roll of distant artillery. At twenty 

 minutes past three, when the darkness reached 

 its greatest depth, the whole city was instan- 

 taneously illuminated by the most vivid flash 

 of lightning ever witnessed in Montreal, im- 

 mediately followed by a peal of thunder so loud 

 and near as to shake the strongest buildings to 

 their foundations, accompanied by a shower of 

 black rain. Very recently a shower of black 

 rain took place in Ireland, which, together with 

 the alarming phenomenon here described, must 

 evidently have had its origin in the existence in 

 the air of impurities of some anomalous kind. 



Occasionally light particles of a more easily 

 explained origin make their appearance in the 

 air. "On the afternoon of June 11, 1847," 

 writes Dr. D. P. Thomson, " the wooded part 

 of Moray shire appeared to smoke, and for a 

 time fears were entertained that the fir planta- 

 tions were on fire. A smart breeze suddenly 

 got up from the north, and above the wood 

 there appeared to rise about fifty columns of 

 something resembling smoke, which wreathed 

 about like water-spouts. The atmosphere now 



