134 PROTEIDS. 



thoroughly, warm for a few minutes, then heat to boiling. 

 Add 3 drops acetate of lead solution, a black pp occurs 

 of lead sulphide. 



Acid albumin. Is less readily formed with strong acids. To 

 some egg white solution (5 in 50) add slowly one-half a volume of acetic 

 acid (B.P. ), agitate, then warm slowly to boiling. 



1. There is no pp on boiling. 



2. Neutralise some of the solution (litmus) with a few drops of KOH 



diluted to one quarter with water, there is a pp of acid 

 albumin. On further adding KOH the cloud disappears. 



3. Boil some of the original solution briskly for a minute, add 



lead acetate solution, there is no black colour. 



Albumoses. 



The substances of interest in this class are physiologically 

 derived from proteids by ferment action in the alimentary 

 canal, and will be taken later with gastric and pancreatic 

 digestion. 



Compound Proteids. 



This very important group contains : 



Haemoglobin. Proteid + Hsematin. Blood. 



Gluco-proteid. ,, + Carbohydrate (animal gum, Land- 



wehr). Mucin of saliva. 



Nuclein. ,, + Nucleic or Phosphoric Acid. Con- 



stituent of nuclei. 



Nucleo-proteid. ,, + Nuclein. Chief constituents of cells. 



Mucin like subst. of bile. 



These will be referred to later, as far as the scope of the 

 work in class allows, under the respective substances in which 

 they occur. 



