466    ANESTHETIC  PRINCIPLE  OP  THE  LYCOPERDON  PROTEUS. 
solutions.  There  being  no  substance  with  which  I  am  acquainted, 
except  carbonic  oxide,  nitrous  oxide,  and  perhaps  some  com- 
pounds of  cyanogen  which  possess  all  these  properties ;  and 
having,  moreover,  in  the  mean  time,  read  a  paper,  by  M.  Adrien 
Ghenol,  "  On  Pure  Oxide  of  Carbon,  considered  as  a  Poison,"* 
it  immediately  occurred  to  me  that  it  was  the  former  of  the  sub- 
stances that  was  the  cause  of  the  narcotism.  I  therefore  specially 
examined  the  fumes  for  carbonic  oxide,  by  agitating  them  with 
an  acid  solution  of  chloride  of  copper,  and  also  by  absorbing  the 
carbonic  acid,  ammonia,  and  oxygen,  by  means  of  lime-water, 
diluted  muriatic  acid,  and  a  solution  of  the  protosulphate  of  iron 
saturated  with  nitric  oxide  gas,  when  indications  of  the  presence 
of  carbonic  oxide  were  readily  obtained ;  the  fumes,  after  agita- 
tion with  the  solution  of  chloride  of  copper,  no  longer  induced 
narcotism  ;  whilst  those,  on  the  contrary,  which  had  been  treated 
with  the  other  solvents,  were  more  than  ordinarily  powerful,  and 
rendered  an  insect  insensible  much  more  quickly  than  before  ; 
they  also  burnt  with  a  blue  flame,  and  possessed  all  the  well- 
known  characters  of  the  oxide  of  carbon.  The  correctness  of 
this  conclusion  was,  moreover,  confirmed  by  experimenting  with 
carbonic  oxide  prepared  by  acting  on  oxalic  acid  with  oil  of 
vitriol,  and  passing  the  gas  evolved  through  caustic  soda-ley. 
Even  when  largely  diluted  with  air,  it  still  continued  to  produce 
insensibility  in  insects,  and  acted  in  every  way  like  the  purified 
fumes  of  the  Lycoperdon.'f 
It  is  not  difficult  to  understand  how  carbonic  oxide  is  formed 
by  the  ignition  of  the  fungus,  as  this  gas  is  invariably  produced 
in  larger  or  smaller  quantity  when  certain  organic  substances  are 
decomposed  by  heat,  though  some  yield  it  in  greater  proportion 
than  others  ;  and  consequently,  as  might  have  been  anticipated, 
1  find  that  the  fumes  of  several  other  fungi  act  in  the  same 
manner  towards  animals  as  those  of  the  Lycoperdon  proteus.  The 
principal  of  those  to  which  I  allude  are  the  common  Ly  coper  don 
of  the  druggist,  L.  giganteum,  and  the  mushroom,  Agaricus 
compestris. — Philosophical  Magazine  for  July,  1855. 
*  Compies  Bendus,  No.  16,  April  17,  1854. 
•("See  also  <  A  Treatise  on  Poisons/  by  Professor  Christison,  4th  edition, 
p.  827,  for  an  account  of  the  peculiar  effects  produced  by  the  inhalation  of 
the  oxide  of  carbon. 
