AnseJPTr-iSiarm'}         The  Organo-metallic  Bodies.  623 
expected,  show  high  poisonous  ^properties,  and  have  had  no  import- 
ant applications  except  as  asphyxiating  gases  in  war. 
Mercury  yields  a  large  number  of  organo-metallic  compounds. 
The  literature  of  this  phase  of  the  subject  is  extensive,  but  until 
recently  has  not  been  collected  in  convenient  form,  as  has  been  that 
relating  to  arsenic  and  antimony.  The  enterprise  of  the  American 
Chemical  Society  has  made  available  a  comprehensive  collection  of 
the  data  concerning  organo-mercury  compounds,  in  a  volume  pre- 
pared by  Dr.  F.  C.  Whitmore  of  the  Northwestern  University,  just 
published.  As  in  the  case  of  the  arsenic  compounds,  the  history 
begins  with  a  somewhat  random  experiment.  In  1843,  A.  W.  Hof- 
mann  distilled  a  mixture  of  aniline  and  mercuric  chloride  and  ob- 
tained a  compound  containing  mercury  in  union  with  a  hydrocarbon 
group,  but  apparently  the  exact  structural  formula  of  this  has  not 
yet  been  ascertained.  In  1850,  Frankland  noted  that  metallic  mer- 
cury acts  on  ethyl  iodide,  later  found  that  methyl  iodide  is  changed 
by  the  same  metal  into  a  methyl  mercury  iodide,  CH3Hgl,  and  that  a 
similar  compound  can  be  obtained  from  the  ethyl  radicle.  A  tragic 
incident  occurred  in  connection  with  the  early  work  on  these  sub- 
stances, for  two  of  the  assistants,  Dr.  Ulrich  and  Dr.  Sloper,  who 
were  working  in  the  laboratory  of  St.  Bartholomew's  Hospital, 
London,  where  the  research  was  being  carried  out,  were  fatally 
poisoned.  Another  London  chemist  accused  Dr.  Frankland  of  sac- 
rificing his  assistants  by  imposing  on  them  this  dangerous  work 
instead  of  doing  it  himsQlf,  and  for  several  months  the  columns  of 
the  Chemical  News  were  hot  with  the  exchange  of  correspondence. 
It  appears,  however,  that  no  blame  can  attach  to  the  chief.  The 
methyl  and  ethyl  compounds  are  liquids  of  high  density,  strongly  re- 
fracting and  dispersive,  and  it  was  thought  that  they  might  be  avail- 
able for  filling  hollow  prisms,  but  their  high  poisonous  qualities 
constitute  a  serious  interference. 
Interest  in  the  study  of  organic  mercury  compounds  has  ^been 
much  increased  for  the  same  reason  that  the  arsenic  compounds  have 
acquired  prominence,  the  use  of  mercury  in  syphilis.  The  need  has 
especially  been  for  non-ionizing  compounds  which  may  be  used  in 
association  with  the  arsenicals.  Just  about  the  time  that  Frankland 
obtained  the  above-mentioned  compounds,  Sobrero  and  Selmi  dis- 
covered another  type.  By  heating  mercuric  chloride  and  potassium 
hydroxide  in  alcoholic  solution,  they  obtained  a  yellow  slightly  ex- 
