110 
GLEANINGS  FROM  THE  GERMAN  JOURNALS. 
Siewert  (Zeitschr.  f.  d.  ges.  Naturwiss.  xviii.)  The  light  blue 
precipitate  obtained  hot  or  cold  from  a  dilute  solution  of  chro- 
mic oxide  by  ammonia,  is  after  drying  Cr2  03  _|-  7  aq.;  dried  in 
vacuo  it  retains  4  aq.,  and  after  heating  to  200  or  220°C.,  with 
the  entire  exclusion  of  oxygen,  it  is  Cr2  03  +  aq.,  of  a  bluer 
color,  with  a  tint  of  grey,  and  insoluble  in  boiling  dilute  muri- 
atic acid.  Heated  to  the  same  temperature  in  contact  with  the 
air,  a  black  powder  is  obtained,  being  a  mixture  of  several  com- 
pounds and  of  variable  composition.  The  pure  hydrate  is  insol- 
uble in  ammonia  ;  a  compound  of  the  two,  however,  may  enter 
into  combination  with  a  salt  of  ammonia,  and  is  then  soluble  in 
ammonia  water.  Fremy's  so-called  metachromic  oxide  still 
contains  ammonia  and  aramoniacal  salt.  A  green  modification 
of  chromic  oxide  does  not  exist ;  the  precipitate  retains  soda  or 
potassa. — (Ibid.  553). 
Crystals  in  Vegetable  Tissues. — Dr.  Fliickiger  (Schweiz. 
Wochenschr.  f.  Ph.  1862.  Nos.  8  and  9)  agrees  with  Kindt,  that 
the  crystals  in  quillay  bark  are  oxalate  of  lime  ;  the  bark  con. 
tains  also  some  tartrate  of  lime.  The  crystals  in  guaiac  bark  are 
likewise  oxalate  of  lime.  Tamarinds  are  free  from  oxalic  acid, 
but  contain  some  starch  ;  the  crystals  which  are  met  with, 
consist  of  tartrate  of  lime. — (Ibid.  569). 
Castor  oil  may  be  given,  according  to  Stan.  Martin,  with  eggs 
to  persons  who  cannot  take  it  in  the  usual  forms.  The  necessary 
quantity  of  the  oil  is  mixed  in  a  flat  pan  with  one  or  two  eggs, 
and  then  heated  with  constant  stirring.  The  Chinese  use  castor 
oil  in  the  preparation  of  their  victuals ;  it  has  no  purgative 
action  on  them,  they  having  become  accustomed  to  its  use  from 
childhood.— (Ibid  572). 
The  reduction  of  salicylous  acid  to  saligenin  may  be  effected, 
according  to  A.  Reineke  and  Beilstein,  by  treating  the  acid  with 
a  little  water  and  sodium  amalgam.  After  several  days,  hydrogen 
commenced  to  be  evolved  and  the  salicylous  acid  had  disappeared 
from  the  alkaline  liquid.  It  was  neutralized  with  sulphuric  acid, 
carefully  evaporated,  and  the  residue  treated  with  alcohol, 
which,  on  evaporation,  left  saligenin,  recognized  as  such,  by  its 
reactions  and  by  ultimate  analysis.  The  following  equation 
shows  its  formation  ;  Cu  H6  04  +  H2  =  Cu  H  04.   If  salige. 
