GLEANINGS  FROM  GERMAN  JOURNALS. 
33 
solutions  the  odor  of  putrid  yeast  appears.  Silicic  acid  does 
not  lose  this  property  by  boiling  with  water  or  by  repeated  em- 
ployment for  fermenting  and  subsequent  washing  with  water. 
A  solution  of  sugar,  containing  alcohol  and  tartaric  acid,  fer- 
mented briskly  with  silicic  acid,  from  which  the  gas  was  evolved, 
and  amid  the  separation  of  a  yeasty  foam. — (Portfolio. — 
Dingler's  Polyt.  Journ.  clxi.  400.) 
Amount  of  silver  in  photographs — Dr.  J.  J.  Pohl,  of  Vienna, 
has  estimated  the  silver  in  positive  photographs  taken  upon 
ordinary  albuminated  paper  ;  after  drying  them,  at  100°  C. 
(212°  F.)  he  found  0-116  per  cent,  equivalent  to  0-125  per 
cent,  oxide  and  0-183  per  cent,  nitrate  of  silver.  The  value  of 
the  material  is,  therefore,  very  insignificant. — (Zeitschr.  f. 
Photogr.  1861,  139.) 
Analysis  of  carbonates  and  black  oxide  of  manganium. — Prof. 
H.  Kolbe  evolves  the  carbonic  acid  from  a  flask,  dries  it  by 
passing  it  over  cotton  and  chloride  of  calcium,  and  absorbs  it 
in  a  Liebig's  potassa-apparatus.  After  thus  determining  the 
carbonate  of  lime  in  the  manganese,  an  excess  of  oxalic  acid  is 
introduced  into  the  flask  and  heat  applied  ;  from  the  amount  of 
carbonic  acid  now  absorbed  by  the  potassa,  the  amount  of  avail- 
able binoxide  of  manganese  is  readily  calculated. — (Ann.  der 
Chem,  und  Pharm.  cxix.  130.) 
Splitting  of  atropia. — Prof.  Ludwig  and  Pfeiffer  endeavored, 
without  success,  to  decompose  this  alkaloid  by  boiling  with  dilute 
sulphuric  acid  similar  to  solania,  (Zwenger  and  Kindt),  but 
on  boiling  it  with  chromate  of  potassa  and  dilute  sulphuric 
acid,  the  liquid  when  of  a  certain  concentration,  turns  green, 
needles  of  benzoic  acid  are  sublimed,  and  the  aqueous  vapors 
excite  to  coughing  from  their  contaminations  with  the  same 
acid.  The  green  residue  when  supersaturated  with  caustic 
potassa,  generates  alkaline  vapors  of  propylamin,  possessing 
the  odor  of  herring  pickle.  The  decomposition  probably  takes 
place  in  accordance  with  the  following  formula  : — 
C34  H23  N06beC14  H8  02+Cu  H6  04+C6  H9  N. 
Atropia  —      nzoic  alcohol  +  benzoic  acid  propylamin. 
(Archiv  der  Pharm.  cvii.  131-132.) 
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