566 
rochleder's  proximate  analysis. 
When  the  methods  of  examination  here  described  have  shown  that  the 
separated  crystals  contain  no  member  of  the  family  of  organic  bases,  and 
no  copulated  compound  which  is  decomposable  by  acids  into  a  carbohydrate 
and  a  second  decomposition  product,  or  by  alkalies,  can  be  broken  up  into 
an  acid  and  a  copulated  carbohydrate,  we  have  to  do  with  an  indifferent 
vegetable  svbstance,  upon  whose  nature  only  an  extended  investigation  can 
afford  a  conclusion. 
There  are  substances  in  the  vegetable  kingdom  which  must  be  reckoned 
among  the  copulated  compounds, hiit  which  donoi  afford  a  carbohydrate  bysplit- 
iingup  by  either  acids  or  alkalies,  for  example,  athamantine.  But  as  such 
bodies  break  up  into  two  products  by  the  action  of  acids  and  alkalies,  we 
arc  already  acquainted  with  their  behaviour  and  nature  by  the  attempts 
made  to  decompose  them  into  a  carbohydrate  and  a  second  body. 
When  we  are  thus  far  acquainted  with  the  crystals,  we  proceed  to  the 
examination  of  the  mother  liquor  from  which  they  have  separated,  which 
must  always  contain  still  a  little  of  the  substance  which  has  crystallized 
out,  as  it  is  impossible  for  the  separation  to  be  total  when  it  has  been 
accomplished  merely  by  crystallization.  But  if  originally  no  crystals  have 
separated,  the  entire  amorplwus  residue  must  be  examined  which  ivas  obtained 
after  the  treatment  of  the  watery  decoction  with  sugar  of  lead  and  subacetate 
of  lead,  and  sulphuretted  hydrogen,  and  evaporation. 
It  has  been  previously  mentioned  that  we  must  endeavor  to  separate  this 
residue,  when  it  has  been  suitably  concentrated  and  treated  with  alcohol, 
into  a  soluable  and  an  insoluable  portion,  and  also  to  treat  the  alcoholic  solu- 
tion with  ether,  to  ascertain  whether  one  or  more  constituents  are  thereby 
precipitated. 
By  the  treatment  of  the  aqueous  decoction  with  animal  charcoal  it 
has  been  ascertained  whether  bodies  are  contained  therein  which 
are  fixed  by  animal  charcoal  or  not.  When  such  bodies  have  been  de- 
tected in  the  decoction  by  means  of  animal  charcoal,  we  must  simplify  the 
method  of  examining  the  residue  in  question  of  the  watery  decoction  which 
has  been  precipitated  with  acetate  and  subacetate  of  lead  by  the  application 
of  animal  charcoal.  If  this  residue  has  been  treated  with  alcohol,  and 
thereby  a  separation  has  been  effected  into  a  part  soluble  and  a  part  in- 
soluble in  alcohol  after  the  evaporation  of  the  alcohol  from  the  part  therein 
insoluble,  and  the  distillation  of  the  alcohol  from  the  part  therein  soluble, 
both  the  resulting  residues  are  separately  dissolved  in  water  and  treated 
with  animal  charcoal.  When  a  precipitate  has  formed  by  the  addition  of 
ether  to  the  alcoholic  solution  of  a  part  of  the  residue,  this  precipitate, 
after  it  has  been  collected  on  a  filter,  as  well  as  the  residue  of  the  filtered 
liquid  freed  from  alcohol  and  ether,  are  dissolved  in  water,  and  the  solu- 
tions treated  with  animal  charcoal.  The  animal  charcoal,  as  before 
described,  is  quite  exhausted  with  alcohol  to  obtain  a  solution  of  the  body 
which  it  has  retained,  which,  after  distilling  off  the  alcohol,  is  examined 
