AmNoT;i878arm'}  Gleanings  from  the  German  Journals.  521 
congealed  in  suitable  moulds.  Since  tannin  cannot  be  combined  with 
this  mass,  E.  Rennard  recommends  the  use  of  Agar- Agar,  a  vegetable 
gelatin  made  in  Japan,  principally  from  Fucus  Amansii.  This  contains 
no  nitrogen,  and  can  also  be  used  for  culinary  purposes.  Rennard 
uses  1  part  of  Agar- Agar,  10  parts  of  glycerin  and  20  parts  of  water; 
the  jelly  is  entirely  transparent,  while  if  made  of  Agar-Agar  and  water 
alone  (1*30),  it  is  opaque. — Pharm.  Ztschr.  f.  RussL,  July  15,  p.  417. 
Hehner's  Method  of  Butter  Analysis. — 185  analyses,  according 
to  Hehner's  method  (see  "Am.  Jour.  Pharm.,"  May,  1878,  p.  257), 
of  pure,  adulterated  and  entirely  artificial  butter,  and  of  different  animal 
fats,  have  fully  convinced  Fleischmann  and  Vieth  that  pure  butter 
yields  a  percentage  of  fatty  acids  varying  between  85*79  ar,d  89*73 
per  cent.  They  consider  butter  yielding  87*5  per  cent,  or  less  strictly 
pure;  if  the  percentage  is  over  875,  but  does  not  exceed  89*73,  tnere 
is  a  possibility,  but  not  a  certainty,  of  an  adulteration.  —  Ztsch.  f.  Analyt. 
Chem.,  1878,  p.  287. 
Starch  in  Cacao. — Wittstein  proved  that  the  starch  naturally  exist- 
ing in  cacao  is  so  enclosed  by  the  fat  and  other  constituents,  that  on 
adding  iodine  to  a  clear  and  filtered  decoction  of  cacao,  a  blue  color 
will  not  be  obtained.  This  furnishes  an  easy  method  of  distinguishing 
between  the  natural  starch  and  starchy  adulterations,  the  filtered  decoc- 
tion of  which  strikes  a  blue  color  with  iodine  — Ztschr.  d.  Allg.  Oest. 
Apoth.  Ver.,  Sept.  1,  1878,  p.  399. 
Explosive  gelatin,  so-called  because  it  resembles  gelatin  in  appear- 
ance, was  invented  by  A.  Nobel  as  a  substitute  for  dynamite,  and  com- 
bines the  advantages  of  being  50  per  cent,  stronger  and  of  not  being 
decomposed  by  water.  It  consists  of  94  to  95  per  cent,  of  nitro- 
glycerin and  5  to  6  per  cent,  of  collodium,  and  is  particularly  adapted 
for  filling  torpedoes,  etc. — Pharm.  Centralh.,  July  18,  p.  271,  from 
Ckem.  Ztg. 
Gold  and  Silver  Plating. — (1.)  Dissolve  10  grams  of  gold  in  40 
grams  HC1  and  15  grams  HN03,  concentrate  and  evaporate  off  the 
acids  as  much  as  possible,  precipitate  the  gold  with  ammonia,  place  on 
a  filter  and  wash.  Dissolve  100  grams  of  potassium  cyanide  in  very 
little  water,  and  dissolve  the  gold  on  the  filter  in  this  solution,  always 
returning  the  filtrate  to  the  filter  until  all  brown  particles  are  dissolved, 
then  add  sufficient  distilled  water  to  make  1  liter. 
