330 



CHEMISTRY OF THE PTOMAINS. 



of the toxalbum ins. The poisonous nature of proteids and the physio- 

 logical action of this base will be described later. 



Pyocyanin, C^JS.^^f>, is the coloring matter of blue pus, and is 

 produced by the action of the bacillus pyocyaneus. It was isolated 

 by Ledderhose (1887) and is said to be an anthracene derivative. 

 On contact with the air it is oxidized to pyoxanthose, a yellow sub- 

 stance. According to Kunz, it contains nitrogen and sulphur. The 

 picrate is of a dark reddish-brown color ; the platinum salt is black, 

 and sometimes is obtained as glittering fine golden needles. 



' Only those bases are here denoted as poisonous which possess a decided toxicity. 



