Am.  Jour.  Pharm.) 
February,  1920.) 
Current  Literature. 
139 
the  sixth  or  seventh  day.  This  is  the  effect  of  the  minimal  lethal 
dose.  When  death  occurs  in  three  hours  and  a  half,  the  blood  shows 
coagulation,  thrombosis,  precipitation  and  agglutination.  Uranium 
thus  does  not  induce  death  directly.  (Plus-Ultra,  Madrid,  August, 
1919;  through  /.  Amer.  Med.  Assoc.,  January  31,  1920.) 
ClinicaIv  Importance  of  the  CoIvLOidaiv  Gold  Reaction. — 
The  main  difficulty  with  the  colloidal  gold  reaction,  Bicke  finds,  is 
the  preparation  of  the  colloidal  gold.  The  trouble  lies  in  the  ex- 
treme sensitiveness  of  colloidal  gold  to  chemical  influences;  even  the 
alkalinity  of  the  glass  may  give  the  solution  a  bluish  tinge  and  render 
it  useless  from  the  start.  Another  frequent  cause  of  failure  is  that 
fresh,  doubly  distilled  water  is  not  used.  The  colloidal  gold  re- 
action furnishes  an  interesting  proof  of  the  baneful  effect  of  ex- 
ceedingly slight  impurities  in  water.  The  main  value  of  the  col- 
loidal gold  reaction  is  that  it  gives  us  a  means  for  the  early  diagnosis 
of  neuro-syphilis.  At  the  Rudolph  Virchow  Hospital,  Berlin,  it 
has  established  the  syphilitic  origin  in  many  obscure  cases.  In 
one  case  of  optic  neuritis,  the  etiology  was  baffling.  The  personal 
and  family  history  was  negative.  The  blood  Wassermann  test  was 
negative,  but  the  colloidal  gold  reaction  gave  the  typical  curve  of 
cerebrospinal  syphilis.  The  patient,  who  was  seriously  ill,  was  at 
once  given  specific  treatment  with  good  results.  If  it  should  prove 
possible  to  simplify  the  preparation  of  the  colloidal  gold,  this  re- 
action might  be  regarded  as  ideal  and  would  be  of  the  greatest  value 
to  medicine.  (Munchener  Medizinische  Wochenschrift,  Munich,  Sept. 
12,  19 19;  through  /.  Amer.  Med.  Assoc.,  January  31,  1920.) 
Pharmacological  Action  of  Cadmium. — Cadmium  is  a  power- 
ful emetic.  Parenteral  administration  of  the  chloride  produces 
nephritis,  and  coagulation  of  protein  and  necrosis  occur  at  the  site 
of  subcutaneous  injection.  The  lethal  intravenous  dose  for  cats, 
rats,  and  rabbits  is  low,  2  to  3.5  Mgm.  of  the  metal  given  as  chloride. 
(Alsberg  and  Schwartze,  /.  Pharm.  Exp.  Therap.,  13:  504,  1919.) 
J.  F.  C. 
Pharmacology  of  Benzaldehyde.— Benzaldehyde  relaxes  the 
tonus  and  inhibits  the  contraction  of  isolated  smooth-muscle  organs. 
It  has  a  vSedative  effect  on  various  organs  in  situ.  It  possesses  definite 
and  marked  local  anesthetic  properties,  anesthetizing  the  sensory 
nerve  ending  of  the  frog's  skin,  of  the  cornea  and  of  human  mucous 
membranes.  Benzaldehyde  solutions  paralyze  nerve  conduction. 
It  is  very  little  toxic.  (D.  I.  Macht,  /  .Pharm.  Exp.  Therap.,  13 :  508, 
1919.)  J.  F.  C. 
