Am.  Jour.  Pharm.l 
March,  1891.  J 
Reactions  of  Albumins. 
147 
cogen  are  insoluble  in  alcohol,  and  are  determined  by  the  difference 
between  the  determined  substances  and  ioo.  The  water,  mineral 
matters,  and  insoluble  substances  are  determined  according  to  Bruy- 
lants'  method  (Joe.  cit).    The  author  adds  the  following  analyses  : 
Peptone  from 
albumin  of 
cleaned  meat. 
Peptone  from 
egg-albumin. 
Peptone  prepared 
directly  from 
meat. 
37'6?5 
34700 
25*857 
31-300 
53*350 
15-964 
9-826 
Unchanged  products,  . 
5*525 
5-93o 
29-972 
Mineral  matters,  .  .  . 
8-285 
1-025 
19-386 
Water,  ........ 
10*250 
4-625 
9-965 
3-980 
NEW  REACTIONS  OF  ALBUMINS.1 
By  C.  Reichl. 
The  author  has  previously  (1889)  called  attention  to  the  color 
reactions  obtained  by  treating  the  albuminoids  with  alcoholic  benz- 
aldehyde  or  salicylaldehyde  in  presence  of  dilute  sulphuric  acid 
and  ferric  sulphate,  and'  has  now  elaborated  his  previous  experi- 
ments and  extended  them  to  other  aromatic  aldehydes. 
Reaction  with  Benzaldehyde. — The  blue  condensation-product 
obtained  on  mixing  egg-albumin,  benzaldehyde,  dilute  sulphuric 
acid,  and  ferric  sulphate,  gives  an  absorption-band  in  the  spectrum 
near  D ;  apparently  it  is  a  compound  of  a  base  with  sulphuric  acid, 
for,  on  adding  an  alkali  to  the  solution,  the  blue  color  disappears 
with  formation  of  a  brownish-white  precipitate,  which  dissolves  in 
acids,  again  forming  a  blue  or  bluish-green  solution.  The  precipi 
tate  dissolves  in  alkalies,  yielding  a  yellow  solution.  The  ferric  sul- 
phate plays  the  part  of  an  oxidizing  agent,  since  dilute  nitric  acid, 
mercuric  oxide,  and  other  substances  which  readily  part  with  their 
oxygen,  may  be  substituted  for  it.  This  reaction  of  albumin 
appears  to  be  due  to  the  scatole-group  contained  in  it,  since  scatole 
itself  gives  a  bluish-violet  coloration  when  similarly  treated. 
Reaction  with  Salicylaldehyde. — When  the  solid  albuminoid  is 
moistened  with  a  05  per  cent,  alcoholic  solution  of  salicylaldehyde, 
1  Monatsh.,  11,  155-165  ;  Jour.  Chem.  Soc.,  1890,  p.  1350. 
