LARIXINIC  ACID. 
557 
aqueous  solutions  is  greatly  increased  by  the  addition  of  either 
acids  or  alkalies.  Larixinic  acid  is  deposited  from  its  aqueous 
solutions  in  crystals,  which  are  very  brittle,  and  often  an  inch 
or  two  in  length.  It  likewise  dissolves  in  cold  alcohol,  but  to 
a  much  greater  extent  in  hot  alcohol.  The  crystals  deposited 
from  its  alcoholic  solutions  are  thicker  and  more  distinctly 
formed  than  those  from  water.  It  also  dissolves  but  sparingly 
in  ether,  and  is  deposited  in  crystals  of  very  considerable  lustre.* 
The  following  are  the  results  of  the  analysis  of  the  larixinic 
acid : — 
I.  0-221  sublimed  acid,  dried  in  vacuo,  gave  04633  carbonic 
acid,  and  0-1003  water. 
II.  0-1993  sublimed  acid  dried  in  vacuo,  gave  0417  carbonic 
acid,  and  0-0913  water. 
III.  0-2272  larixinic  acid,  crystallised  out  of  water,  gave 
0-4756  carbonic  acid,  and  0-1030  water. 
Calculated  numbers.  Found. 
i.  ii.  nr. 
C20=  57.14  57.13    57-06  57-09. 
Hi0=  4-77  5-04     5-09  5-04. 
O10==  38-09  37-83    37-85  37-87. 
From  these  results  it  is  evident  that  the  carbon,  hydrogen, 
and  oxygen  in  larixinic  acid  are  in  the  proportion  of  CoH101, 
or  some  multiple  of  these  numbers,  C20H10O10  being  the  num- 
bers we  have  adopted  as  the  more  probable. 
When  a  quantity  of  larixinic  acid  was  dissolved  in  a  great  ex. 
cess  of  liquid  ammonia,  a  yellow-colored  solution  was  produced; 
when  this  was  evaporated  to  dryness  over  sulphuric  acid  in 
vacuo,  the  larixinic  acid  was  deposited  in  crystals  which  were 
nearly  unaltered.  It  gave  its  characteristic  reactions  with  salts 
of  iron,  and  when  boiled  with  milk  of  lime  gave  off  no  trace  of 
ammonia.  The  combination  which  larixinic  acid  forms  with  am. 
monia  is,  therefore,  so  feeble  that  it  is  decomposed  by  the  vola- 
tility of  the  ammonia.  In  this  respect,  therefore,  and  its  form- 
ing no  hydrate,  larixinic  acid  closely  resembles  both  pyrogallic 
and  oxyphenic  acids. 
*  The  crystals  of  larixinic  acid  catch  fire  readily  and  burn  with  a  bright 
flame,  leaving  no  residue. 
