Am.  Jour.  Pharm. 
Sept.,  1884. 
Chemical  and  Pharmacognostical  Notes. 
481 
pletely  as  possible ;  they  were  then  washed.  Gelatin  made  from  this 
is  not  precipitated  from  its  solutions  by  tannic  acid  unless  a  few  drops 
of  a  solution  of  a  salt  (sodium  chloride,  etc.)  are  added  simultaneously ; 
in  other  respects  it  does  not  differ  from  ordinary  gelatin.  By  boiling 
bones  free  from  mineral  matter  with  repeated  quantities  of  water,  and 
then  dissolving  the  residue  by  heating  with  water  under  pressure,  two 
solutions  are  obtained  which  when  evaporated  to  dryness  at  100°  yield 
two  kinds  of  gelatin  differing  from  one  another  and  also  from  the  above 
variety  in  various  properties. 
Valuation  of  Gelatin. — F.  Prollius  (Dingl.  polyt.  J.  [249],  p.  425) 
has  determined  the  amount  of  ash,  water,  and  insoluble  matter  (residue 
insoluble  in  hot  water)  in  various  kinds  of  gelatin.  To  ascertain  the 
gelatinizing  property  1  part  of  the  sample  was  dissolved  in  90  parts 
of  water,  filtered,  and  the  degrees  of  viscosity  determined. 
Astracan  from  Schmidt  and  Dihlmann, 
Stuttgart  
From  a  collection. 
Fine  iridescent  Russian  quality,  Tu- 
bingen collection  ; 
Russian,  from  Gene  of  Dresden. 
In  laminae,  from  Gehe  
In   threads,  known  as  Hamburg 
threads  1 
Hamburg  isinglass  
Another  quality  
Rolled  northern  fish  bladder 
Iceland] sh  bladder  
Indian  isinglass  
Yellow,  quality  unknown  
Ash. 
Water. 
Insoluble. 
Timerequirec 
for  the  solu 
tion  to  rui 
out. 
per  cent. 
per  cent. 
per  cent. 
seconds. 
0-20 
16  -0 
2-8 ' 
507 
0-37 
18*0 
0-7 
485 
' 
1-20 
17  -0 
1-0 
500 
0-80 
19-0 
3'0 
491 
0-50 
19-0 
0-4 
480 
0-40 
17*0 
1'8 
477 
1-30 
19-0 
2*3 
470 
0-13 
19'0 
5-2 
3-20 
1'5 
10-8 
467 
0-60 
17-0 
21-  (5 
463 
0-78 
18-0 
8'6 
437 
2-30 
17-0 
15-6 
360 
To  judge  of  the  purity  of  isinglass,  it  is  also  recommended  to  subject 
the  sample  to  microscopic  examination. — Ibid. 
Wine  Examination. — (Dingl.  polyt.  J.  [249],  pp.  311-312)  Accord- 
ing to  S.  Kilicsan,  not  only  young  wines  but  old  and  well  kept  wines 
contain  ammonia;  in  six  samples  from  0*0057  to  0'0113  per  cent,  was 
found.    Formic  acid  can  often  be  detected  in  the  distillate  from  un- 
31 
