390 PROTEIN-COMPOUNDS. 



Mulder* ; from the mean of five analyses it was found to 

 contain : 



Carbon 51'9 



Hydrogen 6-64 



Nitrogen 15*09 



Oxygen 26'58 



100-00 



In his most recent memoir Mulder regards this substance as a 

 combination of true teroxide of protein with ammonia, in accord- 

 ance with the formula H 4 NO + 2 (C 36 H 25 N 4 O 13 ) +3HO. 



Preparation. Mulder originally obtained this substance by treat- 

 ing his albumen-protein with chlorine, whereby he obtained the body 

 which he then termed chlorite of protein ; this substance when 

 decomposed with ammonia yielded the body in question. 



He subsequently ascertained that he could obtain it by the pro- 

 longed boiling of fibrin or albumen in water, if freely exposed to 

 the air ; the solution which is thus obtained is filtered and eva- 

 porated, and the residue extracted with alcohol ; the portion inso- 

 luble in alcohol is again dissolved in water and precipitated by 

 basic acetate of lead ; the precipitate after being thoroughly washed 

 is then decomposed by sulphuretted hydrogen, the sulphide of lead 

 removed by filtration, and the solution evaporated. 



Tests. This body has so few characteristic properties, that in 

 the present state of our knowledge it is extremely difficult, if not 

 impossible, to distinguish it with perfect certainty from those 

 substances which frequently occur, although only in small quan- 

 tities, which have been hitherto named extractive matters soluble in 

 water. 



The peptones, ptyalin, pyin, and other little investigated 

 animal matters are very similar to this substance, but differ from 

 it in some of their characters, and hence must not be regarded as 

 identical with it, although many of the differences may be dependent 

 on the admixture of other matters with them. Hence organic ana- 

 lytical chemistry has here a great blank to fill up in order to eluci- 

 date the actual conditions under which this substance occurs. 

 Unfortunately it cannot be obtained in a state of purity from the 

 animal fluids, so that we cannot have recourse to an elementary 

 analysis to confirm our diagnosis. 



* Journ. f. pr. Ch. Bd. 22, S. 340 ; Bull, de Neerlande, 1839, p. 404 ; Ann. d. 

 Ch. u. Pharm. Bd. 47, S. 300-320. 



