THE  AMERICAN 
JOURNAL  OF  PHARMACY 
MARCH,  1Q04. 
METHODS  AND  INTERPRETATION  OF  WATER 
ANALYSIS. 
By  A.  Robin,  M.D., 
Bacteriologist  to  City  Water  Department,  Wilmington,  Del. 
The  average  consumer  judges  of  the  quality  of  the  drinking 
water  by  means  of  his  special  senses  of  sight,  smell  and  taste. 
Water  which  is  turbid  or  emits  a  disagreeable  odor  is  unreservedly 
condemned,  while  clear,  sparkling  water  free  from  odor  is  just  as 
unqualifiedly  pronounced  "  pure."  Those  of  us  who  are  familiar 
with  the  history  of  typhoid  epidemics  and  have  had  opportunity  to 
examine  drinking  waters  by  means  of  special  methods  know  how 
fallacious  such  a  crude  judgment  is.  Water  that  is  clear  and  spark- 
ling may  contain  the  germs  of  typhoid  fever  or  may  be  polluted 
with  sewage  which,  in  the  course  of  decomposition,  gave  rise  to 
carbonic  acid.  It  takes  many  billions  of  bacteria  to  render  a  glass 
of  water  perceptibly  turbid,  and  it  requires  considerable  fresh  sewage 
to  impart  to  it  a  fecal  odor.  On  the  other  hand,  a  turbid  water, 
although  objectionable  from  an  esthetic  point  of  view,  may  be  en- 
tirely wholesome,  and  a  disagreeable  odor  may  be  due  to  inoffensive 
vegetable  compounds  or  harmless  algae. 
This  evident  inability  to  form  a  ready  judgment  of  the  quality  of 
a  drinking  water  has  led  the  sanitarian  to  seek  the  aid  of  the  chemist, 
who,  it  was  supposed,  could  readily  detect  by  means  of  chemical 
analysis  the  injurious  substances  in  the  water  under  suspicion. 
However,  it  soon  became  evident  that  a  chemical  analysis  of  water 
for  sanitary  purposes  differs  essentially  from  any  other  kind  of 
(IOI) 
