AmNov';5fearm-}         Notes  on  Solanace'ons  Bases.  587 
The  yellow  color  is  discharged  by  acidified  stannous  and  chromous 
chloride  solutions.  Analyses  of  the  nitrated  silk  show  that  about 
2  per  cent,  of  nitrogen  is  fixed  in  the  reaction,  probably,  primarily, 
as  the  nitroso-group,  which  the  further  action  of  the  nitric  acid 
converts  into  the  nitro-group,  a  carboxyl  group  being  displaced. 
The  properties  of  the  product  somewhat  resemble  Mulder's  xantho- 
proteic acid,  but  this  contains  more  carbon  and  less  nitrogen,  and 
results  from  a  more  intense  action.  Sulphuric  acid  dissolves  ordi- 
nary silk  gradually  to  a  slightly  colored  solution,  whereas  nitrated 
silk  is  converted  into  a  pale-yellow,  viscid  mass.  Aqueous  potash 
dissolves  ordinary  silk  in  the  cold,  and  nitrated  silk  on  heating  ; 
neither  solution  is  precipitated  by  dilution  with  water,  and  both 
evolve  ammonia  when  heated.  Both  varieties  of  silk  are  dissolved 
by  hydrochloric  acid  and  by  zinc  chloride  solution. 
Ammoniacal  vapors  are  evolved  on  distillation  of  each  variety, 
and  a  carbonaceous  residue  is  left.  On  ignition,  nitrated  silk  burns 
more  rapidly  than  ordinary  silk. 
NOTES  RELATING  TO  THE  SOLANACEOUS  BASES.1 
By  Dr.  O.  Hesse. 
Solanaceous  plants  contain  a  number  of  bases  which  yield  by  the  action  of 
alkalies  or  of  acids  tropic  acid,  or  derivatives  of  that  acid,  together  with  vola- 
tile bases,  and  in  that  respect  present  relations  with  each  other.  Some  of  these 
solanaceous  bases  are  extensively  used  in  medicine,  as,  for  instance,  atropine, 
while  others  are  of  interest  only  in  their  scientific  relations. 
Although  the  preparation  of  these  bases  has  now  acquired  a  high  degree  of 
perfection,  as  may  be  inferred  even  from  the  external  appearance  of  most  of 
the  commercial  articles  now  referred  to,  it  now  and  then  happens  that  these 
articles  possess  characters  which  do  not  quite  agree  with  published  statements. 
These  differences,  as  well  as  Liebermann's  statement2  that  the  volatile  base 
obtained  by  the  splitting  up  of  a  coca  base  is  identical  with  the  pseudotropine 
originally  prepared  from  hyoscine  by  Ladenburg, 3  induced  me  to  undertake  a 
further  investigation  of  this  subject,  the  results  of  which  I  will  now  describe. 
I  have  also  briefly  touched  upon  apoatropine  in  reference  to  the  communica- 
tion of  E.  Merck4  on  that  base,  though  I  have  not  been  able  to  make  any 
experimental  examination  of  it. 
(1)  Atropine. — Under  this  name  published  statements  are  to  be  understood 
as  indicating  a  base  obtained  principally  from  Atropa  Belladonna,  and  melting 
LAnnaIe?i  der  Chemie,  vol.  271,  p.  100.  Reprinted  from  Phar .  Jour .  and  Trans.,  September 
10  and  17. 
'2Berichte,  xxiv,  p.  2339. 
3 Annalen,  cvi,  p.  299. 
4  In  his  Jahresberichte,  January,  1S92. 
