28 Dr C. G. Ehrenberg on the Infusoria and other 



linearis from Chili and North America; Synedra Entomon 

 from Chili. The last occurs also in Africa and Asia. There 

 are no characteristic African species. 



Ehrenberg next mentions facts of a similar kind of earlier 

 date. Humboldt when in Paramo, on the way from Eogota 

 to Popayan, at a height of 2300 toises (14,700 feet), observed 

 a red hail, a fact published by him in the Annales de Chemie 

 for 1825. The height of the place gives peculiar interest to 

 the observation. 



In 1755, on the 14th of October, at 8 o'clock in the morn- 

 ing, a warm Sirocco wind was blowing at Locarno, near Lago 

 Maggiora. At 10 o'clock the air was filled with a red mist, 

 and at 4 o'clock, P.M. there was a blood-red rain, which left 

 a reddish deposit, equal to one-ninth of its mass. There fell 

 9 inches of this rain in one night. About 40 square German 

 leagues were covered with this bloody rain, which also ex- 

 tended on the north side of the Alps into Suabia, and 9 feet 

 of reddish snow fell upon the Alps. Supposing that the de- 

 posit averaged but two lines in depth, there would be for each 

 square English mile an amount equal to 2700 cubic feet. But 

 actual measurement gave for the depth in some places about 

 one inch (or ^th of 9 inches). 



In 1623 there was another blood-rain at Strasburg. It 

 happened on the 12th August, between the hours of four and 

 five in the afternoon. In the year 1222 a similar rain fell 

 at Rome for one day and night. Many other like facts are 

 cited. 



Ehrenberg favours the view of the atmospheric origin of 

 these showers, and speaks of their relation to the fall of 

 aerolites. Chladni, in his work on Meteorites, observes 

 that the stones which fell between 1790 and 1819, amounted 

 to not less than 600 cwt. ; while for the single dust-shower 

 of Lyons in 1846, the material that fell was full 7200 cwt. 

 The Cape Verd shower had a breadth, according to Darwin,* 

 of more than 1600 miles, and according to Tuckey, of 1800 

 miles, and extended 600 to 800 miles, or even 1000 miles 

 from the African coast. This gives an area of 960,000 to 

 1,280,000, or from 1,648,000 to 1,854,000 square miles. 



* Quarterly Jour. Geol. Soc, No. 6, 1846, p. 26. 



