156  PRESERVATION  OF  ANIMAL  AND  VEGETABLE  SUBSTANCES. 
when  diluted  and  carefully  mixed  with  a  few  drops  of  ammonia 
is  converted  into  a  voluminous  deep  blue  precipitate  (very  differ- 
ent from  hydrated  oxide  of  copper),  and  is  soluble  with  a  vio- 
let-blue color  in  an  excess  of  ammonia. 
The  reactions  of  chrysophanic  acid  agree  perfectly  with  the 
above. 
Besides  the  method  above  described,  the  author  also  attempt- 
ed to  prepare  rumicine  by  the  method  recommended  some  years 
ago  by  Rochleder  for  the  preparation  of  chrysophanic  acid  ; 
but  the  solution  of  potash  in  aqueous  alcohol  extracts  from  the 
root,  together  with  the  very  small  quantity  of  rumicine,  so  many 
other  substances,  that  the  subsequent  purification  is  attended 
with  as  much  difficulty  as  in  extraction  by  ether. 
There  is  consequently  no  doubt  that  rumicine  (also  called 
lapathine)  is  identical  with  chrysophanic  acid  ;  and  the  author 
concludes  his  memoir  with  an  expression  of  his  conviction  that 
he  has  wiped  away  two  out  of  the  chaos  of  names  of  imperfectly 
investigated  organic  compounds  Qhem.  Gazette,  Jan.,  1859, 
from  /Sitzungsber.  der  Wiss.  zu  Wien,  xxxi.  p.  26. 
PRESERVATION  OF  ANIMAL  AND  VEGETABLE  SUBSTANCES. 
A  patent  has  lately  been  taken  out  for  effecting  this  object. 
The  improvements  consist  in  coating  animal  and  vegetable  sub- 
stances with  a  compound  formed  of  vegetable  albumen  and  a 
suitable  antiseptic  material.  The  coating  is  effected  by  immers- 
ing the  substances  to  be  preserved  in  the  prepared  compound 
two  or  three  times,  each  coating  being  dried  or  set  in  a  current 
of  air  before  the  next  is  applied.  The  object  of  combining  an 
antiseptic  agent  with  the  vegetable  albumen  is  to  prevent  a  par- 
tial decomposition  of  the  substances  before  the  protective  coat- 
ing is  properly  hardened.  The  following  means  may  be  adopt- 
ed for  carrying  the  invention  into  effect : — supposing  a  joint  of 
meat  to  be  the  substance  to  be  preserved,  the  meat  (with  as 
much  of  its  blood  extracted  as  possible)  is  first  washed  or  im. 
mersed  in  water  impregnated  with  acetate  of  alumina  and  al- 
lowed to  drain  ;  it  is  then  suspended  by  a  string,  and  allowed  to 
descend  into  a  bath  composed  by  placing  about  one  pound  of 
gum  tragacanth  in  from  one  and  a-half  to  two  gallons  of  heated 
