70  Gleanings  from  the  European  Journals \  {A*FeR,  im?" 
solvent  when  chemically  pure,  are  dissolved  to  a  greater  or  smaller 
extent  through  the  influence  of  other  constituents.  His  observations 
lead  him  to  the  conclusion  that  this  principle  is  guaiaconic  acid,  which 
is  present  in  the  crude  resin  to  the  amount  of  about  70  per  cent., 
while  guaiaresinic  acid,  of  which  the  resin  contains  10  per  cent.,  is 
not  colored  by  oxidizing  agents.  The  blue  color  produced  with  pure 
guaiaconic  acid  is  of  longer  duration  if  the  oxidizing  agents,  after 
parting  with  oxygen,  yield  bases  or  indifferent  compounds,  like  per- 
manganic and  ferric  acids,  the  peroxides  of  lead,  manganium,  silver, 
&c. ;  and  it  is  readily  changing,  if  the  oxidizing  agents  produce  acids, 
as  for  instance  chlorine,  bromine,  iodine,  ferric  and  auric  chlorides, 
&c.  A  molecular  change  in  the  constitution  of  this  acid  is  produced 
by  light,  particularly  by  the  direct  sunlight,  even  if  oxygen  is  care- 
fully excluded,  so  that  it  loses  its  property  of  turning  blue  with  oxi- 
dizers. This  shows  the  importance  of  carefully  preserving  a  solution 
of  guaiac  resin,  to  be  used  as  reagent,  from  the  influence  of  light  and 
air.  The  resin  prepared  from  the  wood  by  alcohol  under  exclusion  of 
light  and  air  is  more  sensitive,  and  yields  a  blue  color  of  greater  in- 
tensity and  purity  than  the  commercial  resin.  The  green  coloration 
assumed  by  the  wood  and  resin  on  exposure  is  due  to  the  presence  of 
yellow  coloring  matter  in  addition  to  guaiaconic  acid. —  Wittsteins 
Viert.  Schr.y  1873,  68-74,  from  Schtveiz.  Wochenschr. 
Phosphorescence  of  orris  root — X.  Landerer  has  observed  this  phe- 
nomenon repeatedly  on  digging  at  night  the  rhizome  of  Iris  florentina  ; 
it  occurred  in  the  form  of  luminous  spots. — Ibid.,  76. 
lodal  C4HI302,  discovered  by  Aime  more  than  30  years  ago,  which 
is  obtained  by  acting  upon  iodine  with  a  mixture  of  absolute  alcohol 
and  concentrated  nitric  acid,  is  recommended  by  Guyot  as  an  excel- 
lent anaesthetic,  in  doses  of  one  to  two  and  a  half  grams.  It  is  a 
colorless  oily  liquid,  resembling  chloral  in  odor ;  boils  at  25°  C,  and 
is  decomposed  by  alkalies  into  iodoform  and  formic  acid. — Ibid.,  95, 
from  Journ.  de  Chim.  Med. 
Desiccation  of  egg  albumen. — Stan.  Martin  recommends  the  follow- 
ing as  the  most  expeditious  method :  in  an  airy  room,  well  protected 
from  dust,  a  square  frame  is  placed  upon  two  chairs  or  suspended  by 
cord,  and  a  piece  of  linen  or  muslin  stretched  over  it,  on  which  a 
layer  of  egg  albumen  is  spread.    When  this  is  dry,  a  second,  third 
