606        Detection  of  Ferments  and  Poisons  in  B/ood.{Am'£™^J£*rm- 
medium  was  therefore  resumed,  but  at  first  without  success,  until 
some  small  flat  pieces  of  cultivation  which  had  been  left  dry  and 
unmoistened  in  the  upper  part  of  the  flask,  were  observed  swim- 
ming on  the  top  of  the  liquid,  where  they  developed  most  luxuri- 
antly. In  the  course  of  a  few  weeks  they  formed  over  the  entire 
surface  a  tolerably  thick  whitish  skin,  dry  on  the  upper  side,  which 
eventually  became  moistened,  broke  up  and  sank  to  the  bottom. 
The  product  from  such  a  culture  proved  considerably  greater  than 
that  developed  on  solid  media.  The  cultivation  liquid  used  is  an 
infusion  of  veal  made  faintly  alkaline  and  with  one  per  cent,  of  peptone 
and  4  or  5  per  cent,  of  glycerin  added.  The  bacilli  sown  give 
practically  the  same  results,  whether  taken  from  fresh  or  old  culti- 
vations, from  a  tuberculous  patient,  or  after  passing  through  a  series 
of  animals.  When  the  culture  is  quite  mature,  which  occurs  at  the 
end  of  six  or  eight  weeks,  and  has  been  ascertained  to  be  absolutely 
pure,  it  is  extracted  by  means  of  the  cultivation  liquid  itself,  and 
the  extract  is  evaporated  on  a  water  bath  to  one-tenth  of  its  original 
volume  and  filtered  through  porcelain.  It  then  contains  from  40  to 
50  per  cent,  of  glycerin,  and  is  tested  as  to  its  activity  by  experi- 
ments upon  guinea  pigs. — Phar.  Jonr.  and  Trans.,  Oct.  31,  p.  345. 
DETECTION  OF  FORMLESS  FERMENTS  AND  POISONS 
IN  BLOOD. 
By  Prof.  R.  Kobert. 
Both  the  physiological  and  the  chemico-legal  demonstrations  of 
unstable  poisons  in  blood  encounter  difficulties  depending  mainly 
on  the  fact  that  the  coloring-matter  of  the  blood  (if  the  red  globules 
are  dissolved  by  putrefaction,  morbid  processes,  or  improper  treat- 
ment such  as  the  addition  of  water)  forms  a  tarry  mass  which  it  is 
difficult  to  treat  chemically  and  which  is  perfectly  useless  for  physi- 
ological experiments.  The  removal  of  this  tarry  coloring-matter  is 
generally  effected  by  plentiful  dilution  and  boiling  with  acetic  acid, 
or  precipitation  with  alcohol,  with  potassium  ferrocyanide  and  acetic 
acid,  or  with  uranium  nitrate. 
In  all  these  cases  the  serum  albumen  present  in  the  blood  along 
with  the  blood-pigment  as  well  as  all  albuminoid  enzymes  and  tox- 
albumins  are  simultaneously  precipitated,  and  thus  the  detection 
and  the  isolation  of  the  enzymes  and  toxalbumins  is  rendered 
impossible.    But  if  we  had  an  agent  which  would  throw  down  the 
