354 
Spirit  of  Nitrous  Ether. 
f  Am  Jour.  Pharm. 
\       July,  1877, 
"  British  Pharmacopoeia,"  it  becomes  evident  that  the  changes  made 
were  necessary  in  order  to  secure  a  product  conforming,  as  near  as 
possible,  with  that  of  the  "  United  States  Pharmacopoeia "  of  i860. 
These  changes  at  once  become  evident  on  consulting  the  following  : 
Analytical  comparison  of  the  U.  S.  and  Br.  Ph.  processes  for  preparing  Spirit  qj  Nitrous- 
Ether,  to  which  I  shall  have  occasion  to  refer  in  the  following  pages: 
A.  Weights  and  Measures. 
British.  United  States. 
Measures,  Imperial.  Apothecaries'. 
Weights,  Avoirdupois.  Troy. 
B.  Quality  of  Ingredients. 
British.  United  States. 
Copper,  As  wire.  As  wire. 
Nitric  acid,  sP-gr-  1*42  =75  p.ct.HON05  Same  as  Br. 
Sulphuric  acid,  sp  gr.  1 -843=96  p. ct.  HOS03  Same  as  Br. 
Alcohol,  •        sp.gr.  0-838=84  p. ct.  C4H602  sp.gr.  0-817=92  p. ct.  C4H6(D2 
C.  Quantity  of  Ingredients. 
British.  United  States. 
Copper,  2     oz.=  875-0  grs.  2     oz.=  960  grs. 
Sulphuric  acid,  2    f.oz.=  i6i2-6  grs.  3^    oz.=  i68o  grs 
Nitric  acid,  1st  portion,    2|  f.oz.=  i553  o  grs.  4     oz.=  i92o  grs. 
Nitric  acid,  2d  portion,      j  f.oz  =  310-6  grs.  J    oz.=  240  grs. 
Alcohol,  for  the  reacfn,  20    f.oz  =7332-5  grs.  20    f.oz. =7445  grs. 
Alcohol,  for  dilution,    40    f.oz.  92  f.oz. 
D.    Relation  of  water  to  absolute  alcohol  and  monohydrated  acids. 
British.  United  Statas. 
Absolute  alcohol,  6159  0  grs.  6830-0  grs. 
Water  from  alcohol,  1173-0  grs.  615-0  grs. 
Monohydrated  nit. acid,  13977  grs.  1620-0  grs. 
Water  from  nit.  acid,  465*9  grs.  54°'0  grs. 
Monohydrated  sul. acid,  1561-0  grs.  1624  0  grs. 
Water  from  sul.  acid,  51-6  grs.  55-7  grs. 
Total  weight  of  absol. 
ale.  and  monohy- 
drated acids,  9117-7  grs.  10084-0  grs. 
Tot'i  weight  of  wat'r,  1690-5  grs.  12 10  7  grs. 
Total  weight  of  liquids 
used  in  the  react'n,  10808*2  grs.  1 1295*0  grs. 
Percentage  of  uncom- 
bined  water,  15^64  per  cent.  10*72  per  cent. 
