^VpdCim""*}        Use  of  Preservatives  in  Foods.  161 
I  have  formed  an  opinion,  but  the  data  upon  which  I  have  formed 
the  opinion  are  so  imperfect  that  I  should  prefer  not  to  express  any 
opinion." 
And  further  on,  in  Q.  7432 : 
"  We  are  unable  to  form  opinions  regarding  the  action  of  certain 
drugs  from  their  administration,  either  to  animals  or  to  men,  but  the 
length  of  time  over  which  such  experiments  extend  is  too  short  to 
allow  of  a  complete  opinion  being  formed  in  regard  to  their  action." 
In  7433,  in  answer  to  the  question,  "  Do  I  understand  that  you 
mean  the  cumulative  action  of  such  a  drug  would  not  be  thoroughly 
ascertained  ?  "  he  replied  : 
"  The  cumulative  action,  and  possibly  something  more  than  the 
cumulative  action ;  that  is  to  say,  the  continued  action  over  a  length 
of  time,  even  though  there  should  be  no  accumulation.  To  give  an 
example  of  what  I  mean — if  a  man  takes  a  little  excess  of  sulphate 
of  magnesia  every  morning,  so  as  to  cause  rather  too  free  purgation, 
there  is  no  accumulation  in  the  body  of  the  sulphate  of  magnesia, 
but  yet  at  the  end  of  a  year  the  continued  excessive  use  of  the  drug 
has  given  rise  to  a  condition  of  weakness  which  would  not  have 
been  present  but  for  this  excessive  use,  and  yet  there  has  been  no 
accumulation.  I  thus  distinguish  between  the  cumulative  effect  and 
a  continued  effect." 
"  Q.  7434.  To  take  the  example  of  one  common  preservative — 
boracic  acid ;  the  amount  of  boracic  acid  which  can  be  voided  by 
the  human  subject  in  the  course  of  twenty-tour  hours  is  limited,  is 
it  not? — A.  It  is  limited,  but  I  do  not  know  the  limit. 
"  Q.  7435.  That  is  one  or  the  elements  of  uncertainty? — A. 
Yes ;  that  is  an  element  of  uncertainty. 
"  Q.  7436.  Although  you  might  know  the  exact  quantity  being 
taken  by  a  human  being,  it  would  be  impossible  to  know  whether 
there  was  any  accumulation  going  on  ? — A.  It  would  be  difficult  to 
know  whether  any  accumulation  was  going  on,  and  with  the  present 
data  before  us  it  would  be  impossible  to  say  whether  any  continuous, 
as  distinguished  from  a  cumulative,  effect  was  being  produced. 
"  Q.  7460.  Let  us  take,  for  instance,  a  physician  who  goes  into  a 
hospital  and  prescribes  to  a  patient  10  or  15  grains  of  boracic  acid 
three  times  a  day ;  is  it  a  matter  of  importance  to  the  medical  man 
and  to  the  patient  whether  that  patient  may  already  be  taking  three 
times  that  amount  ? — A.  Yes  ;  I  think  it  is. 
