30 
VARIETIES. 
already  in  active  progress  in  Sardinia. — Franklin  Institute  Journal  and 
London  Builder. 
The  Presence  of  Pyrogallic  Acid  in  Pyroligneous  Acid.  By  Dr.  Petten- 
kofer.—I  have  ascertained  that  wood-vinegar  contains  a  not  inconsiderable 
quantity  of  pyrogallic  acid,  and  have  made  the  discovery  through  the  very 
fine  blue  color  which  salts  of  iron  exhibit  in  crude  wood  vinegar  under  cer- 
tain conditions,  and  which  depends  upon  the  presence  of  pyrogallic  acid,  as 
shown  by  researches  instituted  by  ray  assistant,  M.  Pauli,  which  remains  be- 
hind by  the  evaporation  of  the  vinegar  al  a  gentle  heat,  and  was  obtained  by 
him  in  a  completely  pure  condition  by  sublimation.  , 
This  acid  is  doubtless  produced  from  tannin  by  decomposition  during  the 
dry  distillation  of  the  wood,  and  its  presence  in  wood-vinegar  affords  an  in- 
direct proof  that  the  pine-wood,  which  is  generally  employed  for  making 
charcoal  and  gas,  contains  a  peculiar  tannic  acid. 
Pettenkofer's  discovery  further  explains  why  the  ordinary  malt  vinegar  is 
not  employed  by  calico  printers  and  dyers  for  the  preparation  of  certain 
mordants,  and  particularly  for  acetate  of  iron,  as  the  presence  of  pyrogallic 
acid  in  such  mordants  appears  to  be  necessary  for  the  production  of  certain 
shades  of  color.— Annals  of  Pharmacy,  Oct.  1853,  from  Buchnerh  Reperto- 
riicm.       ,  ' 
P reparation  of  Hydro- Ferrocyanic  Acid.  By  Justus  Liebig. — When  a  cold 
solution  of  ferrocyanuret  of  potassium  i=>  mixed  in  small  portions,  with  its  vol- 
ume of  smoking  muriatic  acid,  asnow  white  precipitate  of  pure  hydro-ferrocy- 
anic  acid,  free  from  potash,  results,  if  the  muriatic  acid  is  quite  free  from  iron. 
This  can  be  washed  with  muriatic  acid  almost  without  loss.  Dried  on  a  tile 
it  dissolves  readily  and  completely  in  alcohol,  and  can  be  obtained  therefrom 
by  the  introduction  of  a  layer  of  ether,  and  standing,  in  beautiful  crystals  free 
from  muriatic  acid.—  Annals  of  Pharmacy,  Oct.  1853. 
Reproduction  of  Cotton  from  Pyroxyline. — The  following  observation  on  the 
restoration  of  cotton  from  pyroxyline,  was  made  by  M.  Bechamp,  Professor 
at  the  School  of  Pharmacy  at  Strasburg.  The  process  consists  in  heating 
pyroxyline,  at  the  temperature  of  boiling  water,  with  a  concentuated  solution 
of  protochloride  of  iron.  The  chlorid  deepens  in  color,  and  very  soon  there  is 
a  disengagement  of  pure  nitric  oxide.  When  this  disengagement  has  ceased; 
the  process  is  ended,  after  washing  the  cotton  with  chlorohydric  acid  to  re- 
move the  peroxide  of  iron  impregnating  the  cotton  fibres. 
By  a  similar  method,  M.  Bechamp  has  succeeded  in  reproducing  amidon 
from  xyloidine,  gum  from  nitric  gum  ;  and  he  has  thus  found  a  process  which 
may  be  applied  without  doubt  to  many  substances  containingnitrogen  in  the 
state  of  NOi. — Silliman's  Journal,  Nov.  1853. 
Administration  of  Ether  in  Capsules. — In  the  Journal  de  Medecine  et  de 
Chirurgie  Pratiques  for  April,  1853,  M.  Clertan,  of  Dijon,  states  that  he 
