Ajn'.  Jour.  Pharni. 
Dec.,  18-6. 
Number  of  Bacteria  in  lee. 
601 
Water,  which  has  been  re-distilled  from  a  mixture  of  about  2  per 
cent,  of  caustic  soda  and  permanganate  of  potash,  (the  first  portions 
of  the  distillate,  if  showing  traces  of  ammonia  when  tested  by  Ness - 
ler's  reagent  having  been  rejected,)  is  mixed  with  about  1  per  cent,  of 
pure  chloroform.  The  alkaloidal  salt  is  to  be  added  and  the  solution 
heated  in  a  flask,  furnished  with  a  thermometer,  to  a  temperature  of 
60°  to  62°  C.  until  all  traces  of  chloroform  have  been  dissipated. 
The  resulting  solution  is  to  be  filtered  through  paper  which  has  been 
folded  ready  for  use,  and  afterwards  been  sterilized  by  heating  to  a 
temperature  of  125°  to  130°  C.  in  an  air-chamber  or  drying-oven,  for 
at  least  one  hour.  Sufficient  of  the  redistilled  water  is  to  be  poured 
through  the  filter  to  make  the  filtrate,  either  weigh  or  measure  accu- 
rately, the  desired  quantity.  Last,  but  by  no  means  least,  the  solu- 
tion is  to  be  preserved  in  vials  which  have  been  washed  with  some  of 
the  same  water  and  dried  at  a  temperature  of  125°  to  130°  C.  or  over. 
The  cork  used,  should  also  be  washed  in  the  redistilled  water,  and 
dried  in  the  same  manner  as  the  vials. 
Solutions  thus  prepared  have  been  kept  for  months  without  show- 
ing signs  of  change. — New  Orleans  Med.  &  Surg.  Jour.,  Oct.  1886. 
ON  THE  NUMBER  OF  BACTERIA  IN  ICE. 
By  Dr.  Carl  Fr^enkel. 
This  research  was  instituted  to  inquire  into  the  representation  of  & 
Berlin  company  for  the  artificial  production  of  ice,  that  natural  ice 
was  dangerous  and  hurtful.  Dr.  Bischoff  had  already  made  chemi- 
cal examinations  of  ice  obtained  from  the  works  incriminated,  and 
had  also  made  some  bacteriological  examinations  of  the  ice,  which, 
however,  were  probably  faulty  in  some  way,  as  for  instance,  keeping 
the  ice  too  long  after  melting.  Bacteria  multiply  rapidly  in  stationary 
water.  It  is  not  necessary  to  detail  here  Dr.  Koch's  method  of 
examination  of  water,  nor  the  precautions  necessary  in  all  bacteria! 
investigation,  but  one  or  two  points  require  notice.  Water  must  be 
examined  at  once  after  collection,  on  account  of  the  rapid  growth  of 
bacteria  in  standing  water.  Moreover,  the  water  examined  must-  be 
shaken  up  before  being  transferred  to  nutrient  gelatin,  on  account  of 
the  tendency  of  bacteria  to  sink  to  the  bottom.  A  number  of  sepa- 
rate examinations  must  be  made  of  any  water,  since  the  number  of 
bacteria  is  liable  to  vary  greatly  day  by  day ;  with  ice  special  precau- 
tions are  necessary.    By  means  of  a  carefully  purified  hammer,  m 
