130 
Deodorization  of  the  Cresols.       (Am.  jour.  Pharm. 
J  1    February,  19 18. 
in  the  solution.  It  is  better  to  leave  a  small  amount  of  calcium  un- 
precipitated  than  to  have  an  excess  of  sulphuric  acid  present.  The 
mixture  is  allowed  to  stand  a  day  and  is  then  filtered,  the  residue 
being  washed  and  the  washings  added  to  the  main  filtrate.  This 
may  then  be  adjusted  to  any  desirable  volume  or  weight.  If  desired, 
a  sample  may  be  analyzed  for  calcium  and  for  sulphonic  acids  in 
the  ordinary  manner  and  the  proportion  of  active  matter  calculated 
as  meta-cresol  monosulphonic  acid  after  subtracting  the  amount  of 
sulphuric  acid  present  as  calcium  sulphate ;  from  which  data  a  stand- 
ard strength  may  be  adopted.  In  practise,  however  it  is  easier  to 
make  the  solution  up  to  the  same  volume  as  the  cresol  originally 
taken  occupied. 
In  this  way  there  is  obtained  a  golden-yellow  liquid  with  at  most 
a  faint  odor  of  leather  but  absolutely  none  of  cresol,  naphthalene, 
pyridine,  or  other  disagreeably  smelling  substances.  In  reaction  it 
is  very  faintly  acid. 
It  consists  of  a  mixture  of  the  monosulphonic  acids  of  the  three 
cresols  of  which  acids  six  are  possible  and  probably  are  all  present 
in  varying  proportions.  As  they  are  very  soluble  in  water  it  is 
difficult  to  obtain  them  in  crystalline  form  and  it  would  be  nearly 
impossible  to  separate  them  one  from  another.  The  relative  power 
of  these  compounds  against  the  lower  forms  of  vegetable  life  has 
not  been  determined,  so  that  I  cannot  state  what  proportions  of  them 
would  be  most  effective.  A  preliminary  titration  of  the  deodorized 
cresol  against  B.  coli  has,  however,  shown  that  the  phenol  coefficient 
of  the  solution  is  considerably  increased  by  the  chemical  treatment. 
Further  investigations  on  this  point  against  other  organisms  and  ex- 
periments to  determine  the  relative  toxicity  of  the  deodorized  cresol 
towards  higher  animals  are  in  progress  and  will  later  be  reported. 
Since  no  addition  of  soap  is  necessary  in  this  formula  and  the 
calcium  salts  of  the  acids  are  all  soluble  in  water  the  compound  will 
not  become  cloudy  when  mixed  with  hard  waters.  This  is  decidedly 
an  advantage  over  the  official  solution.  The  elimination  of  the  soap 
as  an  ingredient  further  makes  it  possible  to  prepare  the  deodorized 
solution  at  a  much  lower  cost.  It  may  be  employed  in  all  cases 
where  the  official  compound  solution  is  now  used  and  with  as  great 
effectiveness  in  the  same  proportions. 
