366  A  New  Mercurial  for  Hypodermic  Use.  {^'^jlS^^'ms''^' 
to  heat  it  to  180°  with  glycerol  to  convert  it  into  solid  pur purin.  This 
rationale  of  the  process  Rosenstiehl  has  explained ;  the  (commercial 
purpurpin contains  pseudopurpurin^  which  possesses  no  tinctorial 
properties^  bnt  is  easily  decomposed  into  carbonic  anhydride  and  pur- 
purin ;  this  latter  dyes  a  brilliant  madder-red.  Rosenstiehl  has 
succeeded  in  separating  the  pseudopurpurin,  and  shows  that  it  is  a 
monocarboxyl-derivative  of  purpurin,  thus  :  purpurin,  Ci4H502(OH)3, 
pseudopurpurin,  Ci4H^02(OH)3COOH. 
This  fact  has  thrown  an  unexpected  light  on  the  practical  industry 
of  the  madder ;  for  it  has  long  been  observed  that  madder  of  Avignon 
gave  a  more  solid  dye-stufP  than  the  madder  of  Alsace.  It  is  now 
shown  that  this  fact  is  due  to  the  greater  quantity  of  lime  in  the 
Avignon  soil,  which  serves  to  eliminate  the  pseudopurpurin  as  a  lime 
compound,  and  prevents  it  being  fixed  to  the  tissue  of  tlie  root. 
It  has  also  been  customary  in  Alsace  to  add  small  quantities  of 
chalk  to  the  dye-baths ;  this  also  prevents  the  fixation  of  the  pseudo- 
purpurin which  passes  into  the  residues,  where  it  may  be  decomposed 
by  sulphuric  acid  and  converted  into  useful  purpurin.  Rosenstiehl  has 
also  studied  madder-orange,  identical  with  the  munjistin  of  Stenhouse, 
and  has  shown  that  it  is  a  monocarboxyl-derivative  of  purpuro- 
xanthin,  bearing  to  it  the  same  relation  that  pseudopurpurin  does  to 
purpurin.  These  researches  also  sho^v  that  the  madder-root  contains, 
besides  alizarin  existing  as  such,  three  glucosides,  viz.,  one  which 
gives  pseudopurpurin  or  purpurincarboxylic  acid,  a  second  which 
gives  alizarincarboxylic  acid,  and  a  third  which  gives  munjistin  or 
xanthopurpurincarboxylic  acid.  The  memoir  presented  to  the  Academy 
contains  a  full  account  of  the  various  substances  obtained  from  madder, 
and  their  physical  properties  as  absorption-spectra. — Jour.  Chem.  8oc. 
1883,  p.  598  ;  Compt  rend.,  96,  465-471. 
A  ^ew  Mercurial  for  Hypodermic  Use.— After  several  years  of 
experimental  and  j^ractical  trials,  Professor  O.  Liebreich  has  at  length 
devised  a  preparation  of  mercury  which  is  especially  serviceable  for  hypo- 
dermic use.  He  announced  his  discovery  at  the  recent  meeting  of  the 
Berlin  Medical  Society.  The  name  of  the  new  compound  is  formamid  of 
mercury,  or  hydrargyrum  formimidatum  solutum.  Liebreich  has  found 
that  about  thirty  injections  of  a  one  per  cent,  solution  suffice  for  ordinary 
cases  of  syphilis.  Given  internally,  the  drugis  inert. — Amer.  Practit.,  Feb., 
1883. 
