j 70  Chloramine  Reactions  of  Proteins.    { Am^/a°r^  ^f9m' 
straw-colored.  A  still  more  delicate  test,  described  here  for  the 
first  time,  is  the  reaction  with  phloroglucinol.  After  clarifying  and 
removing  the  excess  of  lead  as  chloride,  phloroglucinol  is  added.  In 
the  presence  of  caramel  a  brown  precipitate  is  formed.  If  caramel 
is  absent,  the  vanillin  gives  a  delicate  rose-pink  color  or  a  slight 
pink  precipitate.  Clarification  of  the  sample  is  necessary,  as  shown 
by  the  fact  that  the  two  determinations  without  clarification  gave 
high  results. 
Summary. 
Thiobarbituric  acid,  which' is  easily  prepared  from  malonic  ester 
and  thiourea,  may  be  used  for  the  quantitative  determination  of 
vanillin  in  vanilla  extracts  which  do  not  contain  caramel  as  added 
coloring  matter.  When  caramel  is  present  it  may  easily  be  detected 
by  the  brown  precipitate  formed  on  the  addition  of  phloroglucinol 
to  the  clarified  extract  containing  12  per  cent,  hydrochloric  acid. 
CHLORAMINE  REACTIONS  OF  PROTEINS.1 
By  J.  F.  Briggs. 
The  attention  which  has  been  paid  to  the  use  of  hypochlorous 
acid  in  antiseptic  surgery  in  recent  times  has  indicated  the  necessity 
for  a  clear  expostiion  of  the  chemical  functions  of  the  chloramines 
generally  and  of  the  chloramine  derivatives  of  the  proteins  in  par- 
ticular. A  complete  discussion  of  the  clinical  aspect  of  the  subject 
recently  appeared  in  a  paper  read  before  this  society  by  Dr.  T. 
Rettie,2  and  reference  may  also  be  made  to  publications  by  Dakin  and 
others.3  The  object  of  the  present  note  is  to  recall  attention  to  the 
important  researches  of  Raschig,4  in  which  the  reactions  of  the 
chloramine  group  were  outlined,  and  a  process  for  the  preparation 
of  hydrazine  by  means  of  these  reactions  was  established.  About 
the  same  time,  Cross,  Bevan  and  Briggs5  found  in  Raschig's  results 
the  explanation  of  certain  hitherto  obscure  facts  in  connection  with 
flax  bleaching,  and  indicated  the  future  importance  of  this  general 
1  Reprinted  from  Journal  of  Society  of  Chemical  Industry,  December,  1918. 
2  Ibid,,  1918,  23  T. 
3  Ibid.,  1915,  919,  977;  1916,  651. 
*Ber.,  1907,  40,  4586;  Chem.-Zeit.,  1907,  31,  926. 
c  Ibid.,  1908,  261. 
