254    Reducing  and  Oxidizing  Properties  of  Bacteria.  {^Ma^^ilS*"^* 
was  determined  by  measuring  the  quantity  of  hydriodic  acid  produced 
at  the  expiration  of  fixed  times.    The  results  were  as  follows  : 
Temperature=26°— 
After  30  minutes'  action. 
60      "  "  . 
"  150  "  . 
Temperature  60—65°. 
After  30  minutes'  action. 
60      "  "  . 
"     150  "  . 
Temperature=100°. 
After  30  minutes'  action . 
60      "  . 
"    150      "  "  . 
Bilg  prepared  in  thejBilg  prepared  in  the 
dry  way.  wet  way. 
17*5  p.  c.  decomposed 
19-8 
24-  4 
22-5 
25-  4 
307 
22-75 
27-4 
35-1 
17.7  p.  c.  decomposed 
19-  2 
23-9 
20-  1 
251 
33.9 
23-6 
29-9 
35-4 
There  is  therefore  no  appreciable  difference  between  the  rate  of 
decomposition  by  water  of  the  two  specimens  of  bismuth  iodide. — 
Jour,  Chem.  Society,  1888,  p.  137. 
REDUCING  AND  OXIDIZING  PROPERTIES  OF 
BACTERIA.^ 
By  W.  Hekaeus. 
The  author  prepared  pure  cultivations  of  the  various  bacteria  (Ba- 
cilli and  Micrococci),  which  occur  in  river  water,  in  spring  water  and 
in  soil,  and  also  of  the  mould  fungi  (Mucor  and  Aspergillus  flavus). 
Besides  ash  constituents,  the  nutrient  liquids  contained  either  ammo- 
nium carbonate  or  calcium  nitrate  or  carbamide.  There  were  found 
(besides  those  bacteria  that  would  not  grow  in  artificial  liquids)  two 
species  which  reduced  nitric  acid  to  nitrous  acid  and  ammonia,  and 
converted  carbamide  into  ammonium  carbamide;  one  species  which 
made  use  of  nitric  acid  without  reducing  it  to  nitrous  acid,  and  which 
changed  carbamide  into  ammonium  salts  ;  one  species  which  behaved 
similarly  with  nitric  acid,  but  did  not  change  carbamide  into  ammo- 
nium compounds ;  one  species  which  gave  no  indications  of  action  on 
nitrogenous  substances ;  one  species  which  left  nitric  acid  unaltered 
but  changed  carbamide  into  ammonium  salts ;  and  lastly  two  mould 
fungi  which  gave  no  indications  of  action  on  nitrogenous  substances. 
1  Bied.  Centr.,  1887,  783—784.   Eeprinted  from  Jour.  Chem.  Soc,  1888,  p.  313. 
