Prof. Agardh's Memoir on the Red Snow, SfC. 169 



as well as from distillation in alcohol, inferred that it was of vegetable 

 origin, and probably consisted of the farina of some plant, although he 

 could neither account for its having ascended to such elevated regions, nor 

 mention a plant whose farina was of that colour. 



The Italian naturalists who examined that snow which fell in Italy, 

 found that it contained siliceous earth, clay, and an oxide of iron, as well 

 as a considerable portion of some organized substance. This too accords 

 with Sementini's analysis of some bloody rain that fell in Calabria. Upon 

 examining the colouring substance of the red snow discovered by Captain 

 Ross, Wollaston and Thenard came to similar results, and the first was 

 led to conclude that it contained seeds of a moss. 



From the hands of the chemist this substance came into those of the bo- 

 tanist. The celebrated Francis Bauer, in the Journal of Science and 

 Arts, No. xvi. gave a full description of it, and from the similarity in 

 form, as well from chemical comparison, was induced to consider the 

 red snow as a fungus of the genus Uredo, which he calls Uredo nivalis, 

 and nearly related to the Ustilago segetum of Dittm. 



Robert Brown had indeed previously expressed his opinion that this 

 substance had a great affinity to the Tremella omenta of Engl. Bot., and 

 that it might accordingly rank among the Algce. Of this Mr Bauer did 

 not seem to be aware. 



Sprengel's opinion, that it came nearer to Vaiixheria radicata, seems to 

 be farthest removed from the truth. 



On my various examinations of this substance, the question has fre- 

 quently struck me, what might be the true nature of this substance ? 

 without being even able to satisfy my mind upon it, as I had not seen 

 any thing with which I could compare it ; nevertheless, Mr Brown's opi- 

 nion always appeared to be the most correct, namely, that it should be 

 placed with the Algce. 



At length a treatise was communicated to me, from the Royal Academy 

 of Sciences at Stockholm, of Baron Wrangel, upon a new species of lichen, 

 which he called Lepraria kermesiua, but which Linnaeus had confounded 

 with Byssus jolithus. I found a most striking agreement between this 

 new species of lichen and the plant called Uredo nivalis, and expressed 

 this opinion, together with that, that the lepraria was also a true alga. 

 Yet I had not then seen the plant. When, however, I was in Stockholm, 

 in the summer of 1823, Professor Berzelius gave me some of the colour- 

 ing matter of the red snow which he had received from Dr Wollaston, 

 and Baron Wrangel showed me his Lepraria kermesina. The Uredo 

 nivalis was preserved with the snow-water in a small well closed and 

 sealed bottle, which had not been opened from the time it was filled ; yet, 

 after a lapse of five years it retained its red colour, and was not altered 

 in form. The water was perfectly fresh and without smell. When the 

 bottle remained stationary, the substance settled at the bottom of a brown- 

 ish-red colour, two or three lines in thickness, leaving the water per- 

 fectly clear. But, with the least motion, it again mingled with it. 



In order to examine this remarkable substance with more accuracy, 1 



