126 
Iodo-Sulphate  of  Chinioidin. 
Am.  Jour.  Pharm . 
Mar.  1876. 
uncoated  in  seven  hours,  the  sugar  coated  in  eight  hours,  the  gelatin 
coated  in  seven  hours.  I  differ  on  this  point  also  with  Mr.  Remington, 
as  the  digestive  process  of  the  stomach  is  not  agitation,  but  more  pro- 
perly a  churning  or  a  circulatory  displacement  process,  quiet  but  con- 
tinuous in  its  mode  of  operation  ;  hence  my  plan  of  suspending  the 
pills  in  a  large  bulk  of  fluid  arid  allowing  the  bulkier  portion  to  be 
below  the  pills.  Hence,  after  going  carefully  over  the  ground  described, 
and  as  my  tabled  results  will  show,  T  find  that  in  point  of  solubility  the 
Dunton  compressed  pill  surpasses  all  others.  The  second  in  point  of 
solubility  is  the  uncoated  or  officinal  pill  ;  third,  the  sugar  coated  ; 
fourth,  the  gelatin  coated.  Although  there  is  some  difference  between 
the  two  latter,  yet  they  may  be  placed  on  the  same  footing,  as  the  fact 
of  their  being  coated  excipient  pills  must  create  in  the  mind  of  any 
practical  pharmacist  or  intelligent  physician  a  doubt  as  to  their  more 
rapid  solubility  over  a  non-excipient  or  uncoated  pill. 
Philadelphia,  Feb.  14M,  1876. 
ON  IODO-SULPHATE  OF  CHINIOIDIN   AS   AN    EXCELLENT  RE- 
AGENT FOR  THE  QUALITATIVE  AND  QUANTITATIVE 
DETERMINATION  OF  QUINIA. 
BY  DR.  J.  E.  DE  VRIJ. 
Since  I  applied  Herapath's  discovery1  of  the  remarkable  compound 
of  quinia  with  iodine  and  sulphuric  acid  to  the  quantitative  determina- 
tion of  quinia  in  a  mixture  of  Cinchona  alkaloids,2  it  has  often  occurred 
to  me  that  the  use  of  an  alcoholic  solution  of  iodine  has  many  incon- 
veniences, for  it  requires  a  great  deal  of  practice  to  add  the  right 
quantity.  A  slight  excess  of  iodine  is  necessary  to  precipitate  all  the 
quinia  ;  but  if  this  excess  is  too  great,  a  compound  containing  more 
iodine  is  formed,  which  is  very  soluble  in  alcohol.  It  appeared  to  me, 
therefore,  desirable  to  abolish,  if  possible,  the  use  of  free  iodine,  and 
to  obtain  the  same  result  by  using  a  compound  of  iodine.  For  this 
purpose  I  tried  the  most  soluble  of  the  crystallizable  iodo-sulphates 
described  in  Herapath's  paper,  viz.,  the  iodo-sulphate  of  cinchonia. 
The  alcoholic  solution  of  this  compound  added  to  a  solution  of  quinia 
in  alcohol  acidulated  with  sulphuric  acid,  really  produces  a  precipitate 
of  iodo-sulphate  of  quinia  (herapathite),  but  the  bulk  of  the  reagent 
required  to  precipitate  all  the  quinia  was  too  great  to  answer  my  pur- 
1  "  Pharmaceutical  Journal,"  [1]  vol.  xi,  p.  448,  and  vol.  xii,  p.  6. 
2  u  Ibid,"  [3]  vol.  ii,  p.  642.    "  Amer.  Jour.  Phar.,"  1853,  p.  137. 
