DETECTION  OF  PHOSPHORUS 
153 
ble,  the  addition  of  an  equal  weight  of  bi-carbonate  of  potassa 
facilitates  its  solution.  It  is  not  advisable  to  keep  a  permanent 
liquid  preparation  of  polygalic  acid,  leaving  that  form  for  the 
officinal  syrup,  but  it  undoubtedly  offers  an  admirable  means  of 
using  senega  in  the  forms  above  indicated,  when  the  physician 
can  regulate  the  dose  and  associate  it  with  other  remedies  in 
the  nicest  manner. — Proc.  Am.  Pharm.  Association,  1859. 
ON  THE  DETECTION  OF  PHOSPHORUS. 
By  Dr.  Fred.  Hoffman". 
The  author  has  instituted  a  series  of  more  than  one  hundred 
and  fifty  experiments  with  Mitscherlich's  method  for  detecting 
phosphorus.  He  has  mixed  the  phosphoric  mass  of  matches  in 
different  preparations,  with  food  cooked  in  various  ways,  with 
beverages  commonly  used,  and  with  medicines  in  a  liquid,  soft 
and  plastic  state,  and  kept  the  mixtures  for  a  variable  length  of 
time.  The  presence  of  phosphorus,  it  will  be  remembered,  is 
established  by  the  phosphorescence  imparted  to  the  aqueous 
vapors  on  distilling  the  liquid  or  liquified  mixture,  and  the  dis- 
tillation of  the  phosphorus  is  increased  by  the  addition  of  sul- 
phuric acid,  chloride  of  sodium,  sugar,  &c,  whereby  the  boiling 
point  is  made  to  approach  that  of  phosphorus. 
In  the  place  of  Mitscherlich's  apparatus,  the  author  has  con- 
structed a  more  simple  one,  which  is  easily  prepared  and  readily 
taken  apart.  It  consists  of  an  ordinary  flask,  connected  with  a 
receiving  bottle  by  means  of  a  glass  tube,  which  passes  about 
eighteen  inches  through  a  glass  cylinder,  filled  with  cold  water. 
A  long,  straight  tube  conducts  the  gaseous  products  from  the 
bottle.  The  lamp  and  flask  are  surrounded  with  dark  paper, 
and  about  three-fourths  of  the  glass  cylinder.  The  operation  is 
best  performed  in  a  dark  room. 
The  phosphorescence  of  the  liquid  increases  in  intensity  with 
the  consistence  of  the  liquid  and  the  quantity  of  the  phosphorus. 
The  gas  bubbles  are  luminous,  rise  in  the  mixture,  and  appa- 
rently burn  upon  its  surface  with  a  bright  flame.  With  the 
temperature  the  light  i3  increased ;  a  photosphere  fills  the  flask, 
rises  in  the  tube,  and  moves  up  and  down  within  the  cooled  part. 
