AMAugUi;  ml!"-}     Use  of  Hydrate  of  Chloral,  etc.  359 
baryta.  This  was  thought  sufficiently  near  to  the  calculated  number, 
0*642,  to  justify,  when  taken  with  the  preceding  reactions,  the  formula 
C4HC1302,2HS.  It  will  be  seen  that  the  formula  of  the  sulph-hydrate 
is  that  of  the  hydrate,  with  the  water  replaced  by  sulphuretted  hy- 
drogen. 
This  compound  being  decomposed  by  water  or  alcohol  containing 
water,  its  administration  is  difficult.  Quantities  varying  from  0*20 
gram  to  0*60  gram,  in  solution  in  ether,  were  injected  into  guinea 
pigs.  The  effects  noticed  were  a  diminution  of  temperature  of  about 
one  degree  ;  muscular  relaxation  with  peaceable  slumber  for  about  two 
hours ;  no  notable  diminution  of  sensibility,  and  a  slight  acceleration 
of  the  heart's  action.  After  the  slumber  the  animal  returned  rapidly 
to  the  normal  state. — Pharm.  Journ.,  Lond.,  June  29,  1872. 
USE  OF  HYDRATE  OF  CHLORAL  IN  THE  MANUFACTURE  OF 
TRICHLORACETIC  ACID. 
Trichloracetic  acid,  C4C1303H0,  was  discovered,  as  all  chemists 
know,  by  M.  Dumas,  who  obtained  it  by  exposing  in  the  direct  rays 
of  the  sun  large  flasks  containing  crystalline  acetic  acid  and  chlo- 
rine gas  in  the  proportions  of  nine  decigrammes  of  acid  to  each  liter 
of  chlorine.  Afterward  it  was  found  that  it  could  be  made  from 
chloral,  by  oxidizing  it  with  a  mixture  of  chlorate  of  potash  and  hy- 
drochloric acid.  It  has  recently  been  found  that  it  is  sufficient  to 
expose  in  the  direct  sunlight  for  three  or  four  days  a  mixture  of  equal 
weights  of  hydrate  of  chloral  and  fuming  nitric  acid,  allowing  the  ac- 
tion to  go  on  until  the  red  fumes  cease  to  be  given  off.  The  mixture 
is  then  distilled  with  a  thermometer.  When  the  temperature  reaches 
195°  C.  the  heat  is  kept  steady  at  this  point.  The  liquid  distilling 
at  this  point  may  be  considered  as  pure  trichloracetic  acid.  The  for- 
mula for  this  reaction  is  as  follows  : 
2N05      +      C4C1302H    =     2N04    +  C4C1303H0. 
^ Nitric  acid— J    ^—Chloral  hydrate— '  ^— Red  fumes— '  ^Trichloracetic  acid—' 
This  trichloracetic  acid  solidifies  at  44°  C,  and  fuses  at  32°  C.  ; 
its  specific  gravity  is  V618  ;  crystallizes  in  colorless  rhombohedra,  is 
deliquescent,  has  a  feeble  odor,  and  a  sharp,  acid  taste.  It  whitens 
the  tongue  like  oxygenated  water  ;  volatilizes  at  200°  C,  vapor  den- 
sity 5-8.  Instead  of  using  sunlight,  the  chloral  can  be  put  in  a  re- 
tort with  fuming  nitric  acid,  and  at  first  it  gets  warm  and  gives  off 
