592  Valuation  of  Drugs  and  Foods.  {^iXS^3' 
hand,  spirogyra  is  less  sensitive  towards  phenols  than  are  lupines. 
It  seems  to  the  writer  not  at  all  unlikely  but  that  we  have  here 
in  the  possible  application  of  the  work  of  True  and  others  a  field 
with  unusual  opportunities  for  study  in  the  indirect  valuation  of 
some  of  our  potent  drugs. 
(II A)  The  valuation  of  drugs  by  means  of  methods  which  call 
into  play  the  senses  of  the  investigator  has  the  objection  that  the 
personal  element  is  a  variable  one.  Nevertheless,  methods  of  this 
kind  are  still  employed  upon  many  commercial  products  and  have 
a  certain  value  in  their  ready  or  quick  valuation.  While  these 
methods,  as  applied  heretofore,  have  been  more  or  less  crude, 
it  does  not  seem  at  all  unlikely  but  that  the  time  may  come  when 
certain  departments  of  physiology  and  physics  will  contribute  to 
our  more  intimate  knowledge  of  substances  and  their  effects  upon 
the  senses.  This  may  be  illustrated  in  noting  the  taste,  odor,  touch 
and  color  of  the  substance  or  its  solution  in  some  instances. 
The  author  made  some  experiments  to  determine  the  least 
amount  of  substance  which,  when  treated  with  a  proper  menstruum, 
would  give  the  characteristic  taste  or  odor  of  the  drug  employed. 
(i)  The  following  are  the  drugs  upon  which  experiments  were 
made  to  ascertain  the  weakest  solution,  a  few  drops  of  which  would 
still  give  the  characteristic  taste. 
(a)  Nux  Vomica  (containing  2-25  per  cent,  of  alkaloids). — O-IOO 
gramme  of  finely  powdered  nux  vomica  is  shaken  in  the  course  of 
several  hours  with  500  c.c.  of  water.  Ten  c.c.  of  this  solution,  diluted 
with  90  c.c.  of  water,  a  few  cubic  centimeters  still  possess  appreciably 
the  characteristic  taste  of  nux  vomica.  One  c.c.  of  this  solution  is 
calculated  to  contain  0-0000045  gramme  of  the  alkaloids. 
(b)  Cinchona  (containing  7  per  cent,  of  total  alkaloids,  of  which 
3  per  cent,  is  quinine). — 0-500  gramme  of  the  powder  is  mixed 
with  500  c.c.  of  water  as  above,  etc.  Ten  c.c.  of  this  solution  are 
diluted  with  50  c.c.  of  water,  a  few  cubic  centimeters  are  found  to 
still  give  the  characteristic  taste  of  the  alkaloids  of  cinchona.  One 
c.c.  of  this  solution  contains  -000005  gramme  of  quinine,  or  about 
•0000 1 1  gramme  of  total  alkaloids. 
(c)  Aconite  Root  (containing  0*50  per  cent,  of  aconitine). — 0-500 
gramme  of  the  finely  powdered  aconite  is  mixed  with  500  c.c.  of  water 
and  shaken  occasionally  during  the  course  of  five  minutes.  A  few 
cubic  centimeters  of  the  filtered  solution,  if  swallowed,  produce  a 
distinct  and  characteristic  sensation  in  the  throat. 
