504 
Rhus  Michauxii. 
(  Am.  Jour.  Pharm. 
I    November,  1910. 
offered  to  supply  specimens  of  Rhus  Michauxii  from  the  Missouri 
Botanical  Garden  upon  which  tests  could  be  made.  This  was  done 
and  the  material  upon  which  the  tests  hereinafter  described  were 
carried  out  was  obtained  from  this  source.  Having  been  collected 
by  Professor  Trelease  from  an  authentic  specimen  growing  in  the 
Missouri  Botanical  Garden  and  shipped  under  his  supervision,  there 
can  be  no  question  concerning  the  identity  of  the  material  examined. 
The  author  herewith  extends  his  most  sincere  thanks  to  Professor 
Trelease  for  his  courtesies  in  furnishing  the  material  for  examina- 
tion, for  reporting  his  observations  upon  the  living  plant,  and  for 
revising  the  botanical  description  of  Rhus  Michauxii  given  else- 
where in  this  paper. 
EXPERIMENTAL  WORK. 
The  first  lot  of  material  was  received  April  n,  1910.  It  con- 
sisted of  the  ends  of  several  small  branches  with  the  leaf  buds  about 
to  open.  One  of  the  twigs  was  cut  in  small  pieces  and  thoroughly 
crushed  by  bruising  in  a  mortar.  The  disintegrated  material  was 
then  triturated  with  alcohol  for  some  time  and  the  mixture  filtered. 
A  portion  of  the  filtrate  gave  no  black  color  or  precipitate  when 
treated  with  an  alcoholic  solution  of  potassium  hydroxide.  Another 
portion  of  the  filtrate  was  allowed  to  evaporate  spontaneously 
almost  to  dryness  and  a  drop  of  the  syrupy  residue  tested  for  poison- 
ous properties,  according  to  the  method  (slightly  modified)  of 
Tschirch  and  Stevens.20  This  consists  in  thoroughly  rubbing  a 
drop  of  the  suspected  liquid  into  the  integument  of  the  forearm  by 
means  of  a  glass  rod,  thus  covering  a  circular  area  about  1  cm.  in 
diameter.  After  thirty  minutes  the  part  treated  is  washed  with  ether, 
then  with  alcohol,  and  lastly  with  soap  and  water.  If  the  substance 
were  poisonous  the  area  treated  will  exhibit  a  noticeable  redness 
and  perhaps  slight  itching  after  twenty-four  to  thirty-six  hours. 
If  a  negative  result  be  obtained  the  experiment  is  repeated  with  the 
difference  that  the  test  material  is  allowed  to  remain  upon  the  arm 
for  from  one  to  two  hours.  In  doubtful  cases  a  third  experiment 
continuing  through  twenty- four  hours  should  be  carried  out.  When 
tested  by  the  above  method  the  alcoholic  extract  from  the  twigs  of 
Rhus  Michauxii  showed  absolutely  no  poisonous  properties. 
20  Tschirch  and  Stevens:  Arch.  Pharm.,  243,  504  (1905)  ;  also  Am.  Jour. 
Pharm.,  78,  63  (1906). 
