220 
Purification  of  Drinking  Water. 
Am.  Jour.  Pharm. 
May,  1909. 
THE  PROGRESS  OF  THE  PURIFICATION  OF  THE 
DRINKING  WATER  IN  PHILADELPHIA  * 
By  William  George  Toplis. 
It  is  our  great  good  fortune  to  live  in  the  sublime  old  Common- 
wealth of  Pennsylvania.  We  are  justly  proud  of  our  citizenship 
in  the  chief  city  of  this  grand  old  State,  notwithstanding  the  fact 
that  it  has  lately  become  the  practice  of  some  irresponsible  sensa- 
tionalists to  slander  and  villify  her  fair  name.  I  have  wondered  why 
her  people  seemed  so  passive  under  the  lash.  The  spirit  of  non- 
resistance  characteristic  of  her  illustrious  founder  still  remains  to 
counsel  patience  while  waiting  for  a  proper  reply  to  these  wanton 
and  scandalous  attacks.  We  have  at  last  an  answer  in  thundering 
tones,  an  answer  of  splendid  deeds  to  refute  the  frantic  utterances 
of  baseless  charges  and  empty  words.  The  filtration  and  purifica- 
tion of  our  water  supply  is  now  a  fact,  pouring  out  its  inestimable 
blessing  of  two  hundred  gallons  of  clarified,  purified,  and  whole- 
some water  to  each  individual  every  day.  Fourteen  hundred  gallons 
every  week  for  less  than  one  cent.  Seventy  thousand  gallons  every 
year  to  each  one  for  thirty  cents.    That  is  what  filtration  costs  us. 
Before  entering  upon  a  description  of  the  work,  it  is  perhaps 
best  to  make  a  brief  explanation  of  the  fundamental  principles 
underlying  the  system  used  in  purifying  a  city's  water  supply. 
Water  contamination  may  first  be  divided  into  two  great  classes, 
soluble  and  insoluble.  Soluble  contamination  may  again  be  divided 
into  two  classes,  namely,  inorganic  or  mineral  substances,  and 
organic  substances  by  which  is  meant  such  materials  as  are  pro- 
duced by  the  life  process  of  plants  or  animals.  It  is  plain  to  every 
one  that  substances  in  suspension  may  be  removed  from  water  by 
any  well-conducted  straining  process.  It  is  equally  plain  that  sub- 
stances in  solution  are  not  removed  by  any  such  means,  but  remain 
unchanged  in  such  a  filtrate.  As  stated,  two  kinds  of  soluble  con- 
tamination exist,  mineral  and  organic.  Of  these  the  mineral  con- 
tamination plays  but  little  if  any  part  as  a  harmful  factor  in  the 
health  of  the  community.  The  elimination  of  the  disease  producers 
is  the  prime  consideration  in  municipal  water  purification  plans. 
Therefore  from  this  point  of  view  the  presence  of  ordinary  mineral 
*  An  address  delivered  at  the  Philadelphia  College  of  Pharmacy,  April 
20,  1909. 
