ON  SWEET  SPIRIT  OF  NITRE. 
251 
the  D.  of  this  first  portion  was  899—900  at  60°,  and  its  B.  p. 
62° — 64°.  The  temperature  quickly  rose  in  the  distilling  flask 
to  70° — 72°,  and  a  considerable  quantity  came  over,  the  D.  and 
B.  p.  of  which  were  precisely  the  same  as  the  first  portion.  The 
last  portion  came  over  between  72° — 80°.  Its  D.  was  {  00  at 
58°,  and  its  B.  p.  62° — 64p.  Yellow  vapors  appeared  in  the 
distilling  flask,  and  the  small  quantity  of  fluid  left  was  strongly 
acid.  Contrary  to  the  indications  of  the  thermometer,  we  find 
but  one  fluid  partially  decomposed  in  boiling. 
In  "order  to  compare  the  formula  of  the  different  Pharmaco- 
poeias, and  to  do  so  fairly,  the  alcohol  and  N05  made  use  of  by 
each  has  been  reduced  by  calculation  to  dry  alcohol  and  dry 
N05,  taking  for  data  for  these  calculations  the  table  of  Gay 
Lussac,  as  given  in  Prof.  Christison's  Dispensatory,  for  the  alco- 
hol, and  lire's  table  for  NO.-  in  Turner.  The  products  also 
have  been  dealt  with  in  the  same  way,  and  the  loss  of  alcohol 
in  each  process  found. 
The  following  short  tables  will  best  tell  their  own  story  :— 
MATERIALS  USED.  THE  PRODUCT  CONTAINS 
Dry  Alcohol.  Dry  N05  Dry  Alcohol.  AeO-f  N03 
London           28-143              2  982                     17-350  4  140 
Edinburgh       32  547  8  368  21-93  6-975 
Dublin  33-771  3-586  29  54  3-600 
Of  dry  alcohol,  allowing  for  the  hyponitrous  ether,  the  loss  in 
each  process  is : 
London  28-143  less  found  in  product  19-895    =  Loss  8-248 
Edinburgh  32-547        "  "  26-208    =    »     6  339 
Dublin  33-771       "  "  31-757    =    "  2-014 
The  per  centage  loss  is — London,  29-3  ;  Edinburgh,  1947  ; 
Dublin,  5-96.  Taking  the  strongest — the  Edinburgh — as  the 
standard  28-905  =  6-975  of  Ae6+N03,  then  5-58  instead  of 
4-140  ought  to  be  contained  in  the  London,  and  7-99  instead  of 
3-6  in  the  Dublin. 
The  above  numbers  refer  to  weight  and  to  dry  alcohol  and  dry 
AeO+N03;  but  we  have  to  deal  with  the  bulk  and  with  water 
therein,  when  Sp.  Eth.  Nit.  is  dispensed. 
The  bulk  product  of  the 
London  is    28      fluid  ounce,  containing  4-60  of  dry  AeO-f  N03. 
Edinburgh  38-75       •"  "  7-75  " 
Dublin         46-00         «  «  4-00  " 
and  the  medicinal  value  of  these  is  by  bulk — London,  16-48; 
