ELISHA MITCHELL SCIENTIFIC SOCIETY 



37 



A TABLE OF YEARLY MEANS AND RANGES OF BAROMETER 



AT CHAPEL HILL, N. C. 



Years. 



Means. 



Range. 



1854- 

 1855- 

 1856. 



1857- 

 1858. 



1859- 



.30.024 

 .29.985 

 29.977 

 30.047 

 30.106 

 30 125 



1. 12 

 1. 19 

 1.20 



1. 58 

 1.24 

 1.23 



ALTERABILITY OF AMORPHOUS PHOSPHORUS. 



J. C. ROBERTS. 



Authorities are at varience as to the alterability of amorphous 

 phosphorus. Fresenius says : (QuaL AnaL) "Red phosphorus does 

 not alter in air. " Miller, (voL ii, p. 261), " The red phosphorus, if 

 pure, absorbs oxygen slowly, the oxidation being more rapid if the 

 powder is noist; phosphoric acid is formed and from its deliques- 

 cent character, the powder becomes damp. This oxidation occurs 

 so slowly that it was at first imagined that the body underwent no 

 change on exposure to air." Gmelin (vol. ii, p. 109,) says: '*It is 

 unalterable in the air." Fownes (ed'n 1878, p. 216,): " Nor has it 

 any tendency to coit bine with the oxygen of the air." Roscoe & 

 Schorlemmer (vol i, 479): " This substance can be exposed to air 

 for years without undergoing any change. All commercial amor- 

 phous pljosphorous, however, contains traces of the white modifica- 

 tion and this undergoes oxidation in the air so that the mass always 

 has an acid reaction owing to the formation of phosphoric and 

 phosphorus acids." W^tts (vol. vi, 934): "Groves found that 

 amorphous phosphorus whi^h had been kept for two years in a 

 cracked vessel was converted to the extent of 16. p. c. into phos- 

 phorous and phosphoric acids." 



So-called pure amorphous phosphorus, gotten from Marquart in 

 Bonn, was left a year in a loosely stoppered bottle, then a portion 

 of it transferred to a glass-stoppered bottle. At the end of another 

 year it was noticed that the first lot was becoming pasty and deli- 

 quescent, a } in. layer of a yellowish liquid covering the surface 



