30 
Examination  of  Blood  Staiyis. 
/  Am.  Joub.  Pharm. 
t    Jan.  l,  1874. 
THE  EXAMINATION  OF  BLOOD-STAINS. 
A  Commission,  composed  of  MM.  Mialhe,  Mayet,  Lefort,  and 
Cornil,  have  furnished  an  interesting  report  on  this  subject  (Reper- 
toire de  Pharmacie,  July  10th,  1873 ;  Progrls  Medical,  August  23). 
They  point  out  that  in  the  present  day  it  is  no  longer  possible,  in  the 
examination  of  blood-stains  in  legal  medicine,  to  rest  satisfied  with 
the  physical  characters  observed  by  the  naked  eye.  The  microscope, 
sometimes  alone,  but  more  often  associated  with  chemical  analysis 
and  the  spectroscope,  enables  us  to  obtain  an  exact  diagnosis  formerly 
impossible  in  a  great  number  of  cases.    Two  conditions  may  occur. 
1.  When  the  stain  is  of  recent  date  or  supposed  to  be  so,  the  red 
corpuscles  should  be  particularly  examined,  and  every  care  taken  to 
preserve  them  without  change.  The  stains  must  not  be  washed  with 
water,  so  that  the  hgematin  may  not  be  altered.  After  insisting  on 
the  microscopic  characters  of  the  blood-stains,  isolated  or  compared 
with  those  of  various  animals,  the  commission  enumerate  with  care 
the  fluids  which  are  destructive  or  preservative  of  blood-corpuscles. 
Among  the  first,  water,  and  particularly  hot  water,  acetic,  gallic, 
hydrochloric,  and  sulphuric  acids  ;  and  of  alkalies,  potash  and  soda, 
even  in  weak  solution,  and  ether  and  chloroform,  and  many  other 
reagents,  so  alter  the  blood  corpuscles  as  to  cause  them  to  entirely 
disappear.  Alcohol,  chromic  and  picric  acid,  and  bichromate  of 
potash,  preserve  the  corpuscles,  though  they  alter  their  form.  The 
preservative  fluids  are  those  whose  composition  approach  nearest  to 
serum,  such  as  the  iodized  serum  of  Schultze,  an  excellent  preparation, 
made  with  amniotic  fluid,  to  -which  are  added  a  few  drops  of  the 
tincture  of  iodine,  so  as  to  give  it  the  color  of  white  wine ;  or  better, 
a  fluid  composed  thus — white  of  egg,  30  grammes ;  distilled  water,, 
270  grammes  ;  and  chloride  of  sodium,  40  grammes  ;  or  even  a  fluid 
containing  0-5  per  cent,  of  chloride  of  sodium,  or  five  or  six  per 
cent  of  sulphate  of  soda.  If  the  stains  be  wetted  and  softened  by 
these  fluids  and  then  examined,  white  and  red  corpuscles  and  fibroid 
particles  will  be  observed. 
2.  In  more  difficult  cases,  when  the  microscope,  owing  to  the  alter- 
ations which  time  has  effected  in  the  hgematin,  can  give  but  vague 
information,  examination  by  the  spectroscope  and  chemical  analysis 
enables  us  to  arrive  at  precise  results.  The  use  of  these  means, 
being  less  known  and  also  more  delicate,  requires  special  study. 
