62 
NITRIC  ACID. 
atom  by  another  the  similarity  of  physiological  agency,  and  in- 
stead of  similar  crystal-form  analogous  structure  of  the  plants.— 
London  Pharmaceutical  Journal,  from  Annahn  cler  Chemie  und 
Pharmacie. 
WERE  THE  ANCIENT  EGYPTIANS  ACQUAINTED  WITH  NITRIC 
ACID  % 
By  Thornton  J.  Herapath,  Esq. 
In  the  supplement  number  of  the  "Philosophical  Magazine" 
for  July  last,  my  father  published  a  paper  on  "  Early  Egyptian 
Chemistry,"  in  which  he  gave  a  short  account  of  some  experi- 
ments he  had  made  on  certain  hieroglyphical  marks  that  had 
been  discovered  on  the  wrappers  of  a  mummy  which  was  recent- 
ly unrolled  by  Mr.  Nash  at  the  Bristol  Microscopical  Society  ; 
and  he  then  stated  it  was.  his  belief  that  the  ancient  Egyptians 
were  acquainted  with  a  marking  fluid  containing  nitrate  of  silver 
for  its  basis,  and  were  also  familiar  with  the  use  of  nitric  acid. 
A  short  time  afterwards  Mr.  Denham  Smith,  in  reply  to  this 
letter,  took  exception  to  my  father's  views  on  the  subject ;  and 
whilst  admitting  the  interesting  nature  of  the  discovery  that  had 
been  made  of  an  argentine  solution  having  been  employed  some 
three  thousand  years  ago  as  "  marking  ink,"  totally  dissented 
from  the  conclusions  that  had  been  founded  on  it,  inasmuch,  he 
said,  as  there  was  no  evidence  to  prove  that  the  Egyptians  were 
even  acquainted  with  the  art  of  distillations.  He  also  hazarded 
the  opinion,  unsupported,  however,  by  direct  evidence,  that  the 
marking  fluid  in  question  was  prepared — if  I  understand  him 
aright—by  dissolving  either  chloride  or  oxide  of  silver  in  an  am- 
moniac al  solution,  and  consequently  without  the  intervention  of 
any  acid  whatever.  As  the  question  in  dispute  is  one  of  consid- 
erable interest  in  a  scientific  point  of  view,  I  determined  to  sub- 
ject  the  marks  to  a  fresh  examination.  After  making  several 
preliminary  experiments,  I  found  that  no  results  of  any  value 
could  be  obtained  by  the  ordinary  modes  of  analysis,  and  was 
therefore  compelled,  as  a  last  resource,  to  call  in  the  assistance 
of  the  microscope. 
Upon  examining  some  of  the  fibres  of  the  bandages  that  were 
stained  by  the  argentine  ink,  I  found  them  to  present  a  verype- 
