ON  STfEET  SPIRIT  OF  NITRE, 
them  with  a  spirit  of  nitre  which  will  hold  its  integrity  for  a 
longer  time  than  a  week  or  ten  days  ;  and  he  can  comply  with 
this  demand  also.  But  he  cannot  conjoin  the  demands  of  the 
formula  and  the  consumer— one  or  other  must  give  way.  It  is 
surely  bad  policy  to  give  the  wrong- doer  a  good  excuse  for  his 
malpractices.  As  it  is  at  present,  no  honest  manufacturer  can 
advantageously  enter  into  its  preparation,  for  no  one  will  make 
use  of  the  genuine  production.  We  have  never  been  able  to  pre- 
pare a  sweet  spirit  of  nitre  with  20  per  cent,  of  the  AeO-j-NCX 
of  the  Edinburgh  Pharmacopoeia  that  did  not  begin  to  decompose 
within  a  day,  and  when  sent  out  cur  friends  have  found  it,  both 
in  respect  of  strength  and  free  acid,  so  totally  unlike  anything 
they  had  hitherto  met  with,  that  they  refused  to  have  anything 
to  do  with  it. 
Before  leaving  the  spirit  of  nitre  of  the  Edinburgh  Pharma- 
copoeia, we  may  say  that,  while  the  tests  given  for  its  purity  are 
perfectly  accurate,  they  must  be  applied  with  a  caution  that  the 
D.  -847  may  be  given  by  the  addition  of  water,  and  that  the 
solution  of  CaCl  be  such  as  to  contain  about  40  per  cent,  of  dry 
CaCl.  It  is  to  be  observed,  also,  that  the  tests  given  are  only 
applicable  to  a  very  recently  prepared  spirit.  A  sans  pie  made 
according  to  the  Edinburgh  Pharmacopoeia,  on  Jan.  7th,  of  D. 
-817,  and  which  separated  by  half  its  bulk  of  solution  of  CaCl? 
containing  40  per  cent,  of  dry  CaCl,  12  per  cent,  of  AeO-j-N03, 
was  tested  on  Jan.  17  with  solution  of  CaCl  of  different  strengths. 
The  following  are  the  results  : 
Sol.  CaCl  containing  20  per  cent,  dry  CaCl,  sepd.  of  AeO-J-NCg,  8-9  per  cent. 
"  «  30  "  »  11.  " 
"  "  40  «'  "  11.5  " 
*<  u  5Q  u  tc  10.  " 
»'  "  60  "  "  8.    after  two 
hours  in  a  second  experiment,  9  per  cent. 
It  has  already  been  said  that  the  examination  of  some  speci- 
mens marked  "  the  best,"  from  London,  gave  scarcely  a  trace 
of  AeO-J-N03.  This  ought  not  to  be  ascribed  to  adulteration, 
for  experiment  has  shown  us  that  it  is  not  only  possible,  but 
really  the  fact,  that  nearly  the  whole  product  may  be  drawn  over 
before  the  production  of  AeO.-^NG.,  commences.  The  late  Dr. 
Golding  Bird,  many  years  ago,  made  some  investigations  into  the 
nature  of  the  products  left  in  the  retort  alter  the  preparation  of 
