"  7.  Ordinary  filling  is  non-disinfectant.  Hence  the  disinfectant
power  of  the  soap  is  lessened  by  its  presence  and  in  proportion
to  the  extent  to  which  the  soap  is  filled.
"  8.  Soaps  containing  rosin  are  less  disinfectant  than  other  soaps
in  direct  proportion  to  the  amount  of  rosin  present.
"  9.  Too  much  stress  must  not  be  laid  upon  the  disinfectant
power  of  soap  for  clothing.  Strong  soap  solutions  penetrate  with
difficulty,  especially  when  the  meshes  of  the  fabric  are  clogged  with
foreign  bodies.  These,  too,  are  often  just  those  which  cause  the
clothing  to  need  disinfection.  The  solubility  of  the  dirt  in  the  soap
solution,  too,  is  slight  or  nil."

It  will  be  at  once  observed  that  No.  8  is  simply  a  corollary  of
No.  7.  The  difficulty  alluded  to  in  No.  5  can  be  cancelled  by  the
simple  expedient  of  using  a  larger  quantity  of  soap.  Soft  soaps
generally  contain  more  water,  glycerin,  and  other  bodies  which  are
not  soap,  and  are  therefore  inferior  in  disinfectant  power  to  the
hard  soaps.  Colored  soaps,  too,  are  generally  filled  more  than
white  soaps,  and  are  therefore  less  reliable.  It  may  be  regarded  as
certain  that  a  good  washing  with  soap  is  a  very  valuable  disin-
fectant process  when  no  better  can  be  had,  and  the  soap  should
be  used  at  a  high  temperature  and  with  as  little  water  as  practi-
cable. Clothing,  too,  should  be  soaked  for  some  hours  in  the  hot
soap  solution  as  a  preliminary  process.
It  has  been  shown  repeatedly  that  the  soaps  sold  as  dis-
infectant soaps  are  not  more  effective  than  the  ordinary  kind.
