AVa7i;i8H74RM'}      Hydrocyanic  Acid  as  a  Medicine.  21? 
Pharmaceutical  Association,  it  is  impossible  to  procure  sulphuric  acid 
of  this  density.  Upon  actual  trial  with  recently  made  acid,  none  was 
found  to  be  over  1*835  at  60°  F.  The  question  has  arisen,  why  give- 
the  officinal  gravity  of  an  acid,  which  druggists  cannot  make  for 
themselves,  at  a  higher  density  than  the  manufacturing  chemists  can* 
furnish  ? 
I  suggest  as  a  reason  for  this,  that  the  manufacturers  of  sulphuric 
acid  always  advertise  and  sell  their  acid  as  being  of  a  standard  den- 
sity of  66°  B,,  and  the  framers  of  the  Pharmacopoeia,  knowing  this 
to  be  so,  gave  the  corresponding  specific  gravity  at  1-843,  that  being 
the  usual  number  given  in  many  chemical  works  as  equivalent  to  66° 
B.  At  any  rate  I  am  quite  certain  that  if  the  specific  gravity  of  the 
acid,  so  called  66°,  had  been  experimentally  taken  it  would  have 
proved  to  be  only  1-835.  It  is  just  here  that  a  source  of  trouble 
arises.  Any  one  upon  examination  of  the  tables  appended  to  various 
chemical  works,  will  be  struck  with  the  discrepancy  which  occurs  in 
giving  the  specific  gravity  of  Beaume"s  hydrometer — England,  France, 
Germany,  each  have  a  different  scale.  In  this  state  of  uncertainty 
one  of  our  fellow-members,  Wm.  H.  Pemberton,  in  1851  selected  a 
scale  on  this  very  account,  namely,  that  the  strongest  sulphuric  acid 
which  manufacturers  could  readily  make  had  a  gravity  of  not  over 
1*835;  calling  this  gravity  66°B.,  all  the  remaining  degrees  were  readi- 
ly calculated.  From  this  scale,  which  will  be  found  in  the  U.  S.  Dis- 
pensatory, I  have  always  graduated  my  hydrometers,  and  have  for 
23  years  and  over  supplied  nearly  all  the  acid  works  of  our  country, 
thus  fixing  the  density  of  sulphuric  acid  at  66°  B.,  equal  to  1*835 
specific  gravity,  and  which  density  should  certainly  be  that  of  the  of- 
ficinal sulphuric  acid. 
A    PROPOSITION  TO    ABANDON    THE    PRESENT    FORM  OF 
HYDROCYANIC  ACID  AS  A  MEDICINE. 
By  G.  A.  Zwick. 
In  the  February  number,  page  69,  of  the  American  Journal  of 
Pharmacy,  a  series  of  examinations  are  reported  on  the  strength  of 
hydrocyanic  acid  as  met  with  in  commerce.  The  results  of  Mr.  Tow- 
erzey's  experiments  prove  what  always  has  been  surmised  ;  in  fact  any 
one  dispensing  hydrocyanic  acid  must  have  observed  that  the  acid  be- 
comes steadily  weaker  at  each  successive  occasion  to  use  it,  even  though 
not  actually  decomposed. 
