264 
NOTE  ON  CARBOLIC  ACID,  ETC. 
power  is  coming  under  critical  investigation.  Dr.  Angus  Smith 
proposes  colytic,"  which  is  a  good  term,  but  needs  the  natural 
relation  to  the  already  well  established  word  zymotic.  -  This 
relation  is  supplied  in  the  French  word  antizymotique,  which 
is  found  in  Nysten's  Dictionary,  and  is  a  better  word,  though 
perhaps  a  little  less  convenient  than  azymotic,  which  is  proposed 
by  the  writer  and  used  in  this  note.  The  etymology  is  evident, 
and  its  meaning  in  contradistinction  to  antiseptic,  the  nearest 
word  to  it,  is  well  illustrated  in  the  behaviour  of  these  green 
cryptogams. 
The  next  step  in  the  experiments  was  to  separate  the  two 
phenols.  Th  IS  was  a  ccomplished,  perhaps  not  perfectly,  but  as 
far  as  could  be  practically  useful,  by  fractional  distillation  ;  and 
the  cresol  thus  obtained,  but  not  dehydrated,  was  used  in  compe- 
tition with  Calvert's  crystallized  carbolic  acid,  thus  giving  an 
advantage  to  the  latter.  The  sensible  properties  of  the  two  sub- 
stances are  very  different  when  critically  examined,  but  the 
greatest  difference  is  in  solubility.  The  Calvert's  crystallized 
carbolic  acid  used  was,  at  ordinary  temperatures,  soluble  to  the 
extent  of  about  6-6  per  cent.  The  cresylic  acid,  or  cresol,  as 
imperfectly  isolated  here,  was  soluble  to  the  extent  of  only  1*3 
per  cent,  at  the  same  temperatures  and  by  the  same  management. 
Thus  the  saturated  solution  of  Phenol  contained  about  five  times 
as  much  of  this  substance  as  the  saturated  solution  of  cresol. 
Filtered  solutions  of  each,  containing  accurately  one  per  cent., 
were  made  under  the  same  conditions  of  temperature,  etc.,  but 
the  Phenol  had  the  advantage,  first,  because  it  was  dehydrated, 
or  nearly  so  ;  secondly,  because  it  was  pure  and  dissolved  en- 
tirely, whilst  the  cresol  was  not  pure,  or  completely  separated 
from  other  soluble  substances,  and  left  an  insoluble  residue  of  at 
least  two  or  three  per  pent,  (estimated)  upon  the  filter.  The 
same  volumes  of  each  were,  however,  accurately  taken,  namely, 
10  c.  c.  in  the  litre,  the  remainder  being  distilled  water.  Then 
10  c.  c.  of  each  of  these  solutions  was  diluted  with  90  c.  c.  of 
distilled  water ;  and  again  10  c.  c.  of  each  of  these  last  was 
diluted  with  90  c.  c.  of  distilled  water.  These  solutions  then 
contained,  respectively,  ten  parts  in  the  thousand  (jJoo)* 
part  in  the  thousand  {j-^qq),  and  one  part  in  ten  thousand  (yoJo^)* 
