142 
THE  TINNING  OF  SAUCEPANS. 
C23H,,0,o+20-C28H,Oie+6HO. 
In  commercial  tannin  there  is  always  gallic  acid,  and  conse- 
quently ellagic  acid  which  proceeds  from  it.  A  cold  extract  of 
oak  bark  gives  by  degrees  a  yellow  deposit  of  ellagic  acid,  and 
it  is,  indeed,  this  same  acid  which  constitutes  that  gelatinous 
covering  which  is  formed  over  tanned  hides. —  Chemical  News^ 
^..Jan.  22,  1869, /rom  Jo^im.  de  Chim.  Prat. 
THE  TINNING  OF  SAUCEPANS. 
In  France,  as  in  other  parts  of  the  Continent,  the  use  of 
copper  saucepans  is  very  far  more  general  than  it  is  in  England, 
and  great  care  is  generally  taken  to  keep  them  in  good  order. 
In  all  well-conducted  houses  copper  vessels  are  tinned  frequently, 
and  cooks  are  thoroughly  impressed  with  the  danger  accruing 
from  neglect  in  this  respect.  The  police  regulations  require 
that  nothing  but  pure  tin  should  be  used,  but  that  metal  is  dear, 
while  lead  is  cheap,  and  therefore  a  mixture  of  the  two  metals  is 
too  often  made  use  of.  The  mixture  works  well,  but  when  the 
lead  forms  a  considerable  part  of  it  the  vessels  become  decidedly 
dangerous.  In  consequence  of  information  obtained  and  sus- 
picions entertained,  the  Minister  of  War  ordered  an  inquiry  to 
be  made  into  the  subject  by  the  directors  of  the  military  hospitals. 
The  result  of  this  inquiry  has  been  read  before  the  Academy  of 
Medicine,  and  brings  out  the  startling  revelation  that  some 
manufacturers  of  copper  utensils  and  tinners  mix  25,  and  in 
some  cases  50,  per  cent,  of  lead  with  the  tin,  ^nd  that,  in  addi- 
tion to  this,  antimony,  another  dangerous  metal,  is  added.  From 
the  facts  thus  brought  to  light,  M.  Gobley,  a  member  of  the 
Academy  of  Medicine,  has  drawn  up  the  following  list  of  recom- 
mendations : — 1.  That  the  metal  used  to  line  copper  drinking 
vessels  shall  not  contain  more  than  1  per  cent,  of  lead.  2.  That 
not  more  than  5  or  6  per  cent,  of  lead  be  mixed  with  the  tin 
used  for  saucepans  or  other  cooking  vessels,  that  amount  offer- 
ing no  serious  danger.  3.  That  every  maker  shall  be  required 
to  mark  his  productions  with  a  special  stamp.  4.  That  the 
travelling  tinmen  shall  be  strictly  watched. — Chem.  News,  Dec. 
11,  1868, /rom  Journ.  of  the  Society  of  Arts. 
