Am.  Jour.  Pharm. 
June,  1903. 
Progress  in  Pharmacy . 
287 
acid  hexamethylene  tetramine.    (See  Amer.  Jour.  Pharm.,  1902,  p. 
603.) 
Oxygen. — Eugene  C.  Foster,  M.S.,  in  a  recent  number  of  the 
Journal  of  the  Franklin  Institute  (May,  1903,  p.  357),  gives  some 
account  of  the  practical  application  of  the  suggestion,  made  by 
Prof.  Raoul  Pictet  some  years  ago,  that  it  was  feasible  to  separate 
the  constituent  gases  of  liquid  air  by  fractional  distillation. 
The  problem  of  separating  nitrogen  from  oxygen  is  by  no  means 
a  simple  one,  the  boiling  points  of  the  two  substances  differing 
but  12°  Centigrade.  The  process  is  being  developed,  however,  in  a 
commercial  way  at  the  present  time,  it  having  been  found  possible  to 
produce  and  market  a  70  per  cent,  pure  oxygen  at  a  price  no  higher 
than  asked  for  the  ordinary  commercial  50  per  cent.  gas. 
Salicin,  location  of,  in  willow  bark. — Mr.  Daniel  Brown,  in  a  com- 
munication to  the  North  British  Branch  of  the  Pharmaceutical  Soci- 
ety of  Great  Britain  {Client,  and  Drug.,  1903,  p.  651),  gives  the  results 
of  some  experiments  he  has  made  to  determine  the  location  of  the 
bulk  of  the  salicin  in  willow  bark  (Salix purpurea).  One  lot  of  bark 
that  contained  a  total  of  5-8  per  cent,  of  salicin  contained  11-3  per 
cent,  in  the  inner,  8-0  per  cent,  in  the  middle  and  2-5  per  cent,  in 
the  outer  bark.  Another  series  of  experiments  made  by  the  same 
writer  appeared  to  indicate  the  presence  of  a  larger  percentage  of 
salicin  in  the  spring  than  in  the  fall  of  the  year. 
Salocreol,  a  remedy  for  external  application  in  cases  of  facial  ery- 
sipelas, rheumatism,  lymphadenitis  and  other  affections  of  an 
inflammatory  nature.  It  is  said  to  be  composed  of  the  active 
ingredients  of  creosote  and  salicylic  acid,  and  is  a  brown,  oily,  nearly 
odorless  fluid,  almost  insoluble  in  water,  but  readily  soluble  in  alco- 
hol, ether  and  in  chloroform  {Phar.  Post,  1903,  p.  174). 
Tests  for  Heroin. — F.  Zernic  (Ber.  der  Phar.  Gesells.,  1903,  p.  65) 
reviews  the  literature  on  the  physical  and  chemical  properties  of 
heroin.  In  addition  to  a  number  of  reactions  that  heroin  has,  that 
are  similar  to  those  given  by  morphine,  it  has  been  found  that 
heroin  has  a  specific  and  characteristic  behavior  towards  nitric  acid. 
If  we  add  a  few  drops  of  65  per  cent,  nitric  acid  to  a  trace  of  heroin, 
the  latter  is  rapidly  dissolved,  producing  a  yellow  solution  that 
changes  gradually,  very  rapidly  if  heated,  to  a  greenish  blue;  this 
change  appears  to  take  place  from  the  middle  of  the  liquid.  The 
color  then  gradually  fades  until  the  liquid  has  again  changed  to  a 
