136  Minutes  of  PharmaceiiiicaJ  Meetings.   {"MaJcri,  m?"' 
Prof.  Maisch  replied  that  he  did  not  think  there  was  any  change  in  tartar  eme- 
tic, the  bicarbonate  only  neutralizing  any  excess  of  acid  that  may  exist  in  the 
preparation. 
Dr.  Pile  inquired  for  a  practical  test  for  glycerin,  one  that  may  be  employed 
without  delay,  and  with  little  preparation,  one  to  be  proof  against  the  ordinary 
and  most  common  adulterations.  Mr.  Remington,  who  has  been  making  some 
experiments  in  thns  direction,  gave  as  his  experience,  after  the  examiaation  of 
several  (8  or  10)  specimens  of  the  most  prominent  makers,  that  a  glycerin 
which  is  not  discolored  by  nitrate  of  silver  in  solution  was  generally  pure;  the 
nitrate  will  in  5  minutes  show  a  discolorization  should  impurity  exist.  He  con- 
siders that  sulphuric  acid  is  not  thoroughly  reliable  ;  there  is  a  possibility  that 
the  bottle  in  which  it  is  kept  contained  straw,  cork,  or  some  organic  matter, 
upon  which  the  acid  would  immediately  act,  and  possibly  condemn  a  pure  gly- 
cerin in  this  way.  Trommer's  test  may  also  be  applied  to  glycerin,  and  is 
entirely  reliable  in  determining  the  presence  of  sugar. 
Mr.  Shoemaker  produced  a  circular  on  "^therlidon  Chloral,"  used  in  Berlin 
as  a  substitute  for  chloroform,  without  unpleasant  result. 
Prof.  Maisch  gave  the  results  of  his  experiments  with  hydrate  of  chloral 
of  different  makes  generally  known  as  German.  The  experiments  were  made 
with  a  view  to  overcome,  if  possible,  the  disagreeable  pungency  found  on 
opening  almost  every  vial  of  this  salt.  The  pungency  is  probably  due  to  an 
excess  of  hydrochloric  acid.  Attempts  were  made  to  neutralize  this  with 
carbonate  of  ammonia.  This  seemed  to  overcome  the  unpleasantness  for  a 
short  time;  when,  however,  the  bottle  was  again  unstoppered  the  hydrate 
chloral  possessed  the  same  qualities. 
A  sample  of  crystallized  hydrate  of  chloral  was  exhibited.  This  prepara- 
tion is  more  permanent  and  may  be  crystallized  from  bisulphide  of  carbon.  The 
chloral  fuses  by  heating  the  bisulphide  to  about  60  or  65^.  On  cooling,  the 
entire  solution  is  filled  with  crystals.  The  following  process  was  detailed  : 
Take  a  half  gallon  retort,  with  capacious  neck  ;  into  this  place  1  lb.  bisulphide 
of  carbon  and  5  oz.  of  commercial  Ijydrate  of  chloral;  stop  the  neck  of 
retort  with  a  small  piece  of  cotton,  to  prevent  waste  of  bisulphide  ;  place 
the  bulb  of  retort  in  hot  water;  the  chloral  will  first  fuse  ;  agitate  the  retort 
until  entirely  dissolved ;  set  aside  to  crystallize  ;  by  keeping  the  neck  of  retort 
cool  during  process  the  vapor  of  the  bisulphide  when  condensed  will  flow 
back  into  retort;  by  careful  use  the  bisulphide  will  serve  for  several  opera- 
tions. Allow  the  crystalline  mass  to  remain  several  hours  in  retort,  when, 
with  a  glass  rod,  the  crystals  can  be  removed,  dried,  and  are  ready  for  use. 
The  solution  drawn  off  still  contains  chloral,  which  will  in  time  crystallize. 
The  crystals  are  long,  needle-shaped,  sometimes  reaching  2  or  3  inches  in 
length.  Jn  this  form  chloral  is  possessed  or  little  or  no  pungency,  and  is  far 
preferable  for  dispensing  purposes.  By  placing  aqua  ammonia  near  chloral  as 
met  with  in  commerce,  dense  white  clouds  are  formed,  indicative  of  hydrochloric 
acid 
