THE  AMERICAN 
JOURNAL  OF  PHARMACY 
OCTOBER,  1904.. 
f 
THE  THEORY  GF  INDICATORS  AND  ITS  BEARING  ON 
THE  ANALYSIS  OF  PHYSIOLOGICAL  SOLUTIONS 
BY  MEANS  OF  VOLUMETRIC  METHODS. 
By  G.  H.  A.  Clowes,  Ph.D. 
Gratwick  Research  Laboratory,  University  of  Buffalo. 
I.  Introduction. 
II.  Regarding  the  nature  of  indicators  and  theory  of  their  action, 
III.  Behavior  of  indicators  towards  mineral  and  organic  acids. 
IV.  Behavior  of  indicators  towards  bases,  soda,  ammonia,  etc., 
and  the  amido  bases. 
V.  Behavior  of  indicators  towards  proteids,  albumoses,  pep- 
tones, etc. 
VI.  Use  of  indicators  in  titrations  of  normal  stomach  contents. 
VII.  Titration  of  tryptic  digestion  products. 
VIII.  Deductions  obtainable  from  this  work  regarding  the  con 
stitution  of  proteids. 
IX.  Titration  of  blood  serum. 
X.  Titration  of  urine. 
XI.  Summary. 
I.  INTRODUCTION. 
For  a  considerable  period  of  time  clinicians  have  been  in  the 
habit  of  basing  their  diagnoses  of  cancer  and  other  pathological 
conditions  of  the  stomach  to  no  small  extent  on  the  results  obtained 
from  the  chemical  analyses  of  the  contents  of  that  organ.  There  is 
also  an  increasing  tendency  to  titrate  blood  serum,  urine,  etc.,  with 
a  view  to  throwing  some  light  on  the  nature  of  the  pathological 
changes  involved  in  faulty  metabolism.    One  factor  which  has  eris- 
(453) 
