Am.  Jotjiw  Pharm.  } 
Dec.  1, 1874.  $ 
Varieties. 
581 
shape :  Lignum  quassiae  has  often  a  fusty  smell  and  a  corresponding 
taste;  this  I  attributed  to  the  presence  of  some  form  of  fungus  growth 
— and  most  probably  the  fungus  is  a  penicillium — and,  assuming  this 
to  be  so,  the  probability  is  that  some  of  the  spores  have  got  into  the 
fluid,  and  have  been  slowly  and  silently  effecting  the  conversion  of 
the  alcohol  into  acetate  of  ethyl.  It  is  this  fact  which  constitutes 
the  point  of  interest,  for  if  the  alcohol  had  only  become  changed  into 
acetic  acid,  the  presence  of  fungi  or  anything  else  would  not  have 
been  necessary,  but  the  change  is  of  a  more  complex  and  delicate 
character.  The  amount  of  acetic  acid  present  is  only  small,  and 
much  diluted,  but  the  odor  of  the  ether  is  powerful.  The  next  point 
was  to  prove  the  theory  I  had  set  up,  and  I  proceeded  to  examine 
the  sediment  microscopically.  With  a  one-fifth  objective  it  looked 
like  granular  amorphous  matter,  mere  points,  without  structure.  But 
sufficient  was  shown  to  determine  that  it  was  not  inert  matter,  and, 
on  submitting  it  to  the  amplifying  power  of  800  or  900,  its  nature 
was  clearly  and  beautifully  displayed  ;  it  was  made  up  entirely  of 
unicellular  organisms,  of  a  somewhat  irregular  roundish  form,  about 
one-third  the  size  of  a  yeast  cell,  and  having,  like  that,  one  or  more 
nuclei.  Besides  these  cells,  were  a  considerable  number  of  bacteria, 
or  vibrios. 
To  mycologists  there  is  another  point  of  interest  I  will  mention  ; 
these  exceedingly  minute  bodies,  when  viewed  by  reflected  light,  look 
opaque,  and  of  a  drab  or  grey  color,  and  are  not  globular,  but  flat- 
tened on  two  sides.  These  flattened  sides  have  raised  edges  and 
slightly  raised  centres,  something  like  the  top  of  a  pork  pie. 
August,  1874. 
— Pharm.  Journ.  and  Trans.  [Lond.~],  Sept.  12,  1874. 
uxhtim. 
Determination  of  the  Freezing- Point  for  Delicate  Thermometers — Dr.  G-. 
Krebs. — Schultz,  in  his  treatise  on  the  freezing-point  of  the  water  of  gaseous 
solutions  and  the  regelation  of  ice,  shows  that  the  freezing-point  of  water  is 
lowered  by  dissolving  gases,  the  change  being  nearly  proportional  to  the 
amount  of  gas  dissolved.  That  water  holding  solids  in  solution  freezes  at  a 
lower  point  is  well  known.  Thomson  and  Clausius  have  shown  from  the 
principles  of  the  mechanical  theory  of  heat  that  the  freezing-point  of  water 
falls  0  007°  C.  for  every  additional  atmosphere  of  pressure.  To  determine  the 
true  freezing  point,  take  a  glass  tube  closed  at  one  end,  20  centimetres  long, 
and  2  wide,  fill  it  almost  full  with  sulphuric  acid,  and  heat.  Then  pour  out  the 
acid,  and  rinse  repeatedly  with  pure  distilled  water.  The  tube  is  then  two- 
thirds  filled  with  distilled  water,  which  has  been  boiled  for  some  time  in  a 
clean  beaker,  and  a  small  quantity  of  filtered  oil  of  turpentine  (about  one  cen- 
timetre in  depth)  is  poured  upon  the  water.   The  tube  is  then  carefully  heated 
