ON  TOBACCO. 
213 
out,  or  showed  scarcely  any  decolorization.  The  remainder  had 
become  more  or  less  brown,  on  the  upper  surface  principally, 
scarcely  on  the  lower.  They  possessed  a  simple  herbaceous 
odor,  no  pungency  like  that  of  ammonia,  or  commercial  leaf,  but 
a  decidedly  acrid  taste. 
One  hundred  and  seventy-one  grains  of  the  green  leaves  were 
exhausted  with  boiling  alcohol, — dilute  alcohol  acidulated  with 
hydrochloric  acid, — and  the  alcohol  removed  from  the  tincture 
by  distillation.  The  residue  indicated,  when  tested  wTith  tenth 
normal  solution  of  iodohydrargyrate  of  potassium,  (one  cubic  cen- 
timetre =0-00405  of  a  gramme=  0-0625  of  a  grain  of  nicotina,) 
2-345  grains  of  the  alkaloid  in  171  grains.  1-36  p.  c.  of  the 
dry  leaf=  0-1836  p.  c.  in  the  fresh. 
Six  hundred  and  sixty  grains  of  the  leaves  which  had  become 
somewhat  tainted  were  treated  in  precisely  the  same  manner. 
They  indicated,  within  a  mere  fraction  of  9-37  grains  of  alkaloid, 
=  1-42  per  cent,  in  the  dry,  =  0-1917  per  cent,  in  the  fresh 
state. 
Of  the  fresh  leaves,  the  juice  of  which  was  of  a  very  decided 
acid  reaction,  28-5  troyounces  had,  at  the  same  time  been  placed 
in  digestion  at  a  moderate  temperature  for  several  days,  with 
water  acidulated  with  sulphuric  acid.  The  3700  cc.  of  liquor, 
resulting,  contained,  according  to  assay,  28-87  grains  of  nico- 
tina, equal  to  0-21  per  cent,  in  the  fresh  state. 
Ten  troyounces  of  the  same  were  macerated  in  the  same  man- 
ner ;  the  resulting  liquor,  however,  evaporated  in  a  porcelain  dish 
to  the  consistence  of  soft  extract,  and  after  redissolving  tested 
with  iodohydrargyrate;  this  indicated  4-75  grains;  only  0-1 
per  cent  were  still  present. 
Commercial  tobacco,  known  as  Connecticut  seed-leaf,  and  re- 
ported to  be  of  the  same  variety  and  neighborhood  as  the  fresh 
plants  under  examination,  presented  the  usual  properties  of 
good  tobacco.  Its  simple  watery  infusion  was  decidedly  alka- 
line. Hydrogen  gas  and  still  more  air  at  a  slightly  elevated 
temperature  passed  over  the  tobacco  contained  in  a  long  tube, 
carried  olf  very  noticeable  quantities  of  nicotina  and  ammonia. 
On  distilling  it  with  water,  the  vapors  carried  over  nicotina,  am- 
monia and  its  carbonate,  and  it  was  observed  that  the  whole 
of  the  nicotina  contained  in  a  watery  infusion  could  be  evolved 
