492  Abstracts  from  the  French  Journals.    {Am- oT/iw*™' 
certain  point,  of  being  confounded  with  the  tint  which  a  trace  of  mor- 
phine would  have  given.  The  use  of  reagents  containing  a  large  ex- 
cess of  sulphuric  acid  (molybdate,  vanadate,  selenite,  etc.,)  is  made 
very  uncertain  by  the  presence  of  ptomaines.  We  obtained,  in  fact, 
colorations  of  variable  tones,  reddish,  sometimes  violet,  and  oftener 
identical  with  those  which  sulphuric  acid  alone  would  have  given. 
With  bichromate  and  sulphuric  acid  we  saw  produced  on  a  single  oc- 
casion only,  a  violet  tint  analogous  to  that  which  a  trace  of  strych- 
nine would  give.  With  alcoholized  sulphuric  acid  and  ferric  perchlo- 
ride,  certain  residua  gave  greenish  tints,  which  could  be  confounded 
with  the  coloration  given  by  digitalin  in  like  conditions.  It  is  im- 
portant therefore,  to  take  account  of  the  various  causes  of  error,  but 
we  must  not  exaggerate  their  importance.  The  colorations  due  to  the 
ptomaines  are  never  in  fact  so  clear  and  so  evident  as  colorations  of 
the  same  kind  produced  by  vegetable  bases.  If  we  remember  that  a 
single  color-reaction  would  not  suffice  for  the  official  conclusions  of  the 
expert,  and  that  he  would  also  have  to  depend  upon  the  agreement  of  a 
group  of  chemical  or  physiological  signs,  we  will  see  that  the  chances  for 
error  are  in  reality  infinitely  small.  But  if  it  appears  to  us  altogether 
improbable  that  the  medico-legal  expert  would  confound  a  ptomaine 
with  a  vegetable  base,  it  is  also  very  certain  that  the  presence  of  the 
ptomaines  would  obscure,  in  a  large  measure,  the  clearness  of  reaction 
in  the  toxic  alkaloids  which  might  really  exist  in  the  extraction  made ; 
and  consequently  that  small  quantities  of  these  alkaloids  might 
remain  unperceived.  The  complete  purification  of  the  residua,  the 
separation  of  the  ptomaines  and  the  vegetable  bases  is,  therefore,  for 
toxicological  research,  a  problem  of  the  highest  importance,  and  one 
whose  solution  is  yet  to  be  found.— Archives  de  Pharmacie,  August  5, 
1887. 
Lanolin  v.  lard. — Experiments  made  with  a  view  of  determining  the 
relative  value  of  lanolin  in  promoting  absorption  through  the  skin  have  been 
reported  upon  by  Dr.  Guttman  in  the  Med.  Ohron.,  potassium  iodide  and 
salicylic  acid  being  used,  as  being  readily  detected  in  the  urine.  Ointments 
of  equal  strength,  made  with  lanolin  and  with  lard,  were  used  upon  four 
different  patients,  and,  in  the  subsequent  examination  of  the  urine,  the  most 
frequent  and  distinct  indications  of  the  absorption  of  the  iodide  or  of  sali- 
cylic acid  were  found  after  the  use  of  the  lard  ointment.  At  any  rate,  the 
results  are  considered  to  prove,  at  least,  that  lanolin  possesses  no  superi- 
ority over  lard  in  promoting  the  absorption  of  potassium  iodide  or  salicylic 
acid  through  the  skin. — Am.  Pract.  and  News. 
