48 
Preparation  of  Mustard  Oils. 
(  Am.  Jour.  Pharm 
\      Jan.,  1883. 
As  the  amoimt  of  carbon  and  nitrogen  is  so  excessively  small  in  any 
ordinary  contaminated  water,  evil  effects  resulting  from  the  use  of  such 
a  water  cannot  be  due  to  chemical  compounds,  but  rather  to  living 
organisms  present  at  the  same  time.  The  presence  of  nitrates  is  not 
sufficient  evidence  for  the  condemnation  of  a  water,  but  rather  that  of 
nitrites,  which  may  be  due  to  a  special  ferment,  which  is  itself  capable 
of  propagating  disease.  From  the  presence  of  chlorides,  contamination 
by  animal  or  vegetable  matter  must  only  be  determined  with  great 
caution.  At  present,  attempts  to  determine  the  source  of  the  contami- 
nation, whether  animal  or  vegetable,  have  not  been  followed  by  very 
satisfactory  results.  Biological  experiments  show  that  such  waters  as 
are  dangerous  to  animal  life  have  a  high  C  :  JN"  ratio.  Tidy  considers 
that  the  putrescent  or  easily  oxidizable  substances  are  of  animal  origin, 
whereas  those  less  easily  putrescent  are  vegetable  matters.  The  author 
does  not  wholly  agree  with  him,  as  he  tinds  that  the  proportionate 
consumption  of  oxygen  within  the  first  hour  is  rather  greater  for  those 
waters  containing  vegetable  than  for  those  containing  animal  matter, 
whilst  one  of  the  co-workers  in  this  investigation — Smart — considers 
that  the  gradual  evolution  of  albuminoid  ammonia  (Wanklyn's  pro- 
cess) indicates  organic  matter,  whether  vegetable  or  animal,  in  a  fresh 
condition,  whereas  a  rapid  evolution  indicates  putrescent  organic 
matter.  Finally,  it  is  not  possible  to  decide  absolutely  on  the  whole- 
someness  of  a  water  by  the  mere  estimation  of  organic  matter.  All 
samples  should  be  examined  without  delay,  as  great  changes  may  occur 
in  the  composition  of  the  water,  but  samples  should  also  be  kept  for  10 
or  12  days,  and  then  examined,  and  their  composition  compared  with 
that  of  the  fresh  sample. — Jour.  Chem.  Soc,  Dec,  1882,  from  Chem. 
News. 
Preparation  of  Mustard  Oils. — A.  "W.  Hofmann  states  that  the 
mustard  oils  are  best  prepared  from  the  disubstituted  sulpho-ureas  by 
treating  them  with  a  concentrated  aqueous  solution  of  phosphoric  acid. 
The  sulpho-ureas  are  easily  obtained  by  treating  carbon  bisulphide 
with  the  amines.  Starting  with  carbon  bisulphide  and  aniline  we  get 
diphenyl-sulpho-urea,  CS(CgH5)2H2N2 ;  and  when  this  is  treated  with 
phosphoric  acid  it  breaks  up  directly  into  aniline  and  phenyl-mustard 
oil,  thus : 
CS(CeH,),H,N,=C,H,(NH,) + C,H,NCS, 
Mustard  oil. 
— Amer.  Chem.  Jour.,  Oct. ;  Ber.  d.  Deutsch.  Chem.  Ges.  [15],  985. 
