POPULAR MISCELLANY. 



707 



waters near Madeira had a peculiar obscu- 

 rity, which was occasioned by numerous 

 minute tufts of oscillatoria waving in the 

 mass. These plants were found all the 

 way to the West Indies, sometimes thick 

 enough to give a color to the water, but 

 never wholly wanting. In other cases the 

 sea is colored red by animals of different 

 kinds, by minute crustaceans or infusoria?, 

 or eggs. The name of Red Sea or Vermil- 

 ion Sea has been given to two different 

 phenomena in the Gulf of California, in 

 which the water is colored two distinct 

 shades of red by different microscopic infu- 

 soriae. One of the coloring animals is irri- 

 tating to the skin, and produces blisters 

 and sores on the bodies of those who come 

 in contact with it. Diatoms often give rise 

 to similar colorings. Professor Cleve, of 

 Upsala, mentions fifty-four species of di- 

 atoms which have been found on the surface 

 of the Sea of Java, and speaks of others 

 which have been observed between Europe 

 and Greenland and in Davis Strait. Gru- 

 now gives a list of thirteen species which 

 are found near the Nicobar Islands. Kjell- 

 mann gives especial attention to the diato- 

 maceous flora in his treatise on the alga of 

 the Kara Sea. The Swedish polar expe- 

 dition of 1872-"73 saw on the northwestern 

 coast of Spitzbergen an expanse of sea of 

 considerable extent covered with masses of 

 diatoms of a single species, forming what 

 the English sailors call a " sawdust sea." 

 The same has been observed in Davis Strait, 

 in the Kara Sea, and on the northern coast 

 of Finland, covering large spaces. Jo- 

 hann Steenstrup found spots in the Atlan- 

 tic Ocean between Scotland and Greenland, 

 where the water changes from ultramarine 

 to an emerald green, so suddenly that only a 

 line separates the two colors. The coloring 

 seems to have some relation to temperature, 

 the green prevailing in the warmer months, 

 the blue in the colder, and is thought to be 

 connected with the development of diatoms. 

 Professor Ossian Sars, of Norway, has ob- 

 served a dull grayish-green color of the sea, 

 which he ascribes to a bathybius that he 

 found floating on the surface of the water. 

 Similar colorings occur in fresh water, and 

 have received the names at times of bloody 

 rains, bloody dews, etc. Schwammerdam, 

 observing water thus strangely colored at 



Yincennes, was strongly affected by the 

 sight, but, examining it, found that the color 

 was given by small crustaceans. The Hus- 

 ten Lake in Switzerland has been colored 

 by oscillatoria which were so thick in the 

 water as to make it unhealthy for the fish, 

 and to cause them to die ; the fishermen are 

 well acquainted with the phenomena, and 

 speak referring to the mixture of green and 

 red of the lake blooming. The water in 

 one of the lakes of Denmark has been found 

 colored a deep red by another oscillatoria. 

 In still other cases the colors are given by the 

 spores of an alga. The so-called " bloody 

 rain " is colored by an alga, which, because 

 they have not noticed it before, some believe 

 to have come down from the clouds, while 

 others think it was previously present but 

 was dried up, and has only been refreshed 

 and enlivened by the rain. It has re- 

 cently been identified with the "red snow," 

 a one-celled, spherical plant, green or red 

 in color, which may be increased by di- 

 vision, and is propagated rapidly in water 

 or melting snow. In the still waters of 

 the coast of Denmark a red deposit appears 

 on the decaying sea-weeds, or floats loosely 

 on the surface, giving a raspberry-red color 

 to the water. It is caused by bacteria, 

 which, probably contributing to the decay of 

 the sea-weed, are thought to have a part in 

 the formation of the sulphuretted hydrogen 

 gas so common in that region. Of a simi- 

 lar character caused by vegetable or ani- 

 mal growths, often by bacteria are the 

 colored spots which appear on decaying 

 food ; and it can no longer be considered 

 an occasion of marvel that a pond becomes 

 as red as blood, or that what seem to be 

 drops of blood may appear on the sacra- 

 mental wafers. These phenomena are all 

 assignable to natural causes which have 

 been traced out and are clearly known. 



Luminous Paint. The invention of lu- 

 minous paint is based upon the fact that 

 certain substances after having been exposed 

 to the light will continue to shine for some 

 time after the light is removed. The exist- 

 ence of this power in some gems has been 

 known for a long time, and is mentioned in 

 some of the works of the ancients. Japan- 

 ese antiquaries tell of a luminous stone that 

 was dug out of the ground in a. d. 669. 



