NOTE  ON  CARBOLIC  ACID,  ETC. 
26T 
same  phenols  used  for  the  cryptogams,  namely,  Calvert's  crystal- 
lized medicinal  carbolic  acid  No.  2,  and  the  cresol  imperfectly 
separated  and  prepared  by  the  writer.  Among  the  many  persons, 
probably  twenty,  to  whom  these  solutions  were  presented,  only 
two  or  three  failed  to  detect  both  the  phenols  in  solutions  which 
contained  one  part  in  ten  thousand  of  distilled  water.  The 
whole  of  the  ten  persons  relied  upon  detected  the  Phenol,  or 
"  crystallized  acid,"  in  a  solution  which  contained  one  part  in 
twenty  thousand,  though  all  did  not  detect  it  every  time  they 
were  tried,  and  many  failed  to  detect  it  when  tried  soon  after 
having  tasted  a  stronger  solution.  One  observer  only  could 
detect  the  "  crystallized  acid"  in  a  solution  of  one  part  in  fifty 
thousand,  and,  although  his  testimony  is  unequivocal,  his  evi- 
dence is  unsupported.  No  one  gave  the  slightest  evidence  of 
taste  in  a  solution  of  one  part  in  one  hundred  thousand  parts  of 
distilled  water.  Every  one  of  the  ten  persons  relied  upon  de- 
tected the  cresol  in  a  solution  of  one  part  in  one  hundred 
thousand  parts  of  water  every  time  it  was  submitted  to  a  fresh, 
clean  palate  for  trial,  and  generally  detected  it  even  after  other 
trials.  Five  of  the  ten  persons  easily,  promptly  and  repeatedly 
detected  the  smoky  taste  of  the  cresol  in  a  solution  of  one 
part  in  two  hundred  thousand  parts  of  distilled  water,  and 
detected  it  so  promptly  as  to  show  that  this  was  not  the  limit  of 
easy  detection,  although  this  was  the  most  dilute  solution  tried. 
This  solution  is  in  the  proportion  of  1  c.  c.  in  200  litres,  or 
about  Ib^  grains  in  52  gallons. 
These  results  lead  to  the  conclusion  that  to  the  ordinary  sense 
of  taste  the  cresol  is  from  five  to  ten  times  stronger  than 
the  Phenol.  How  far  this  single  series  of  experiments  may 
be  safely  accepted  it  is  difiicult  to  decide,  but  their  indica- 
tion is  unequivocal  that  the  azymotic  power  in  the  two  phenols 
is  very  different,  and  is  in  favor  of  the  cresol  in  about  an 
inverse  proportion  to  the  degree  of  solubility  in  water.  That  is 
to  say,  that  the  azymotic  power  of  the  saturated  solutions  is 
somewhere  about  equal,  whilst  the  saturated  solution  of  Phenol 
holds  five  times  as  much  of  that  substance  as  a  saturated  solution 
of  the  other  does  of  cresol.  Should  subsequent  investigation 
establish  any  dependent  relation  between  aromatic  odorous  sub- 
stances and  antiseptic  efiects,  these  differences  between  Phenol 
