AmApri]r;Sarm"}  The  Chlorinated  Compounds  of  the  U.  S.  P.  205 
This  appears  to  be  due,  in  a  great  measure,  to  the  two  operations 
of  filtration  which  are  embodied  in  the  present  official  process,  and 
in  both  of  which  cases  the  residue  is  very  difficult  to  exhaust  com- 
pletely. 
Given  the  same  degree  of  care  and  attention,  the  1880  process 
affords  a  better  preparation  in  a  shorter  time,  both  of  which  results 
are  of  unquestionable  advantage. 
After  an  experience  of  manufacturing  over  300  gallons  of  the 
preparation,  within  three  weeks  (to  be  used  in  the  flooded  districts 
of  Pennsylvania  during  the  spring  of  1894),  it  is  the  opinion  of  the 
writer  that  the  1880  process,  which  was  used  after  one  trial  of  the 
present  process,  which  trial  proved  unsatisfactory,  is  by  far  the  better 
of  the  two,  as  it  was  found  by  using  it,  that  a  preparation  containing 
a  larger  percentage  of  available  chlorine  could  be  made  with  a 
decided  saving  of  both  time  and  labor.  It  also  occurred  at  the  time 
that  the  injunction  to  dispense  a  clear  liquid  was  somewhat  unnec- 
essary, as  the  liquid  syphoned  off,  while  still  slightly  cloudy,  was  by 
no  means  unsightly  ;  and  the  filtration  which  was  necessary  to  pro- 
duce a  clear  liquid,  without  waiting  for  it  to  settle,  added  to  the 
time,  labor  and  cost  of  preparation,  while  it  in  no  wise  added  to  its 
good  qualities. 
While  working  upon  this  subject  a  few  experiments  were  also 
made  to  test  the  validity  of  the  following  assertion,  which  is  made 
in  the  United  States  Dispensatory,  page  825.  "  When  it  (solution 
of  chlorinated  soda)  is  boiled,  chlorine  is  not  given  off,  nor  is  its 
bleaching  property  sensibly  impaired,  and  when  carefully  evaporated 
a  mass  of  damp  crystals  is  obtained,  which,  when  redissolved  in 
water,  possesses  the  properties  of  the  original  liquid." 
The  following  experiments  were  performed  with  the  accompanying 
results. 
The  first  sample  was  evaporated  upon  a  water  bath  almost  to  dry- 
ness, the  residue  dissolved  and  water  added  to  restore  the  original 
volume.    The  loss  was  1*205  Per  cent,  of  available  chlorine. 
Sample  number  two  was  evaporated  to  a  small  volume  in  an  air 
bath,  temperature  6o°  C,  and  redissolved  as  before.  The  loss  of 
available  chlorine  amounted  to  -597  per  cent.  The  third  sample 
was  evaporated  to  complete  dryness  in  the  air  bath,  and  the  original 
volume  restored  as  in  the  previous  cases.  The  loss  was  I  644  per 
cent,  of  available  chlorine.    These  experiments  show  that,  while 
