AmjJu°i?!'"i904frm'}      Latent  Power  in  the  Laboratory.  325 
classification  must  necessarily  be  preliminary  and  tentative,  and  that 
improvements  in  laboratory  technique  will  often  result  in  transfer- 
ring certain  subjects  into  that  class  in  which  the  student  has  the 
inestimable  advantage  of  direct  personal  contact  with  the  phenomena 
to  be  studied.  Indeed,  there  is  nothing  more  encouraging  to  those 
who  are  engaged  in  working  out  these  educational  problems  than 
the  discovery  that  medical  students,  under  proper  instruction,  can 
be  safely  trusted  to  employ  the  most  refined  methods  of  physiologi- 
cal research.  Thus  in  the  Harvard  Medical  School  capillary  electro- 
meters have  been  manufactured  by  the  hundred  and  used  success, 
fully  by  first-year  students. 
It  seems  to  me,  therefore,  evident  that  the  reaction  against  purely 
didactic  methods  of  instruction  is  a  movement  to  be  heartily  wel- 
comed ;  but,  like  all  other  reforms,  it  should  be  carefully  guided,  lest 
useful  as  well  as  useless  things  be  swept  away.  It  should  be  borne 
in  mind  that  it  is  quite  as  possible  to  abuse  the  laboratory  as  the 
didactic  method  of  instruction,  and  that,  in  all  schemes  of  education, 
a  good  teacher  with  a  bad  method  is  more  effective  than  a  bad 
teacher  with  a  good  method. 
THE  LATENT  POWER  IN,  AND  THE  INFLUENCES 
EMANATING  FROM,  THE  LABORATORY. 
By  Prof.  R.  H.  Chittenden, 
Director  of  the  Sheffield  Scientific  School,  Yale  University. 
Where  could  be  found  a  more  striking,  more  convincing  demon- 
stration of  the  great  advancement  made  of  late  years  in  the  develop- 
ment of  the  scientific  branches  of  medicine  than  the  present  labora- 
tories afford.  So  long  as  medicine  and  the  related  sciences  were 
crude  and  inexact,  so  long  as  our  knowledge  was  based  mainly  upon 
theories  and  hypotheses  of  doubtful  origin,  and  still  more  question- 
able value,  the  laboratory  counted  for  little.  As  scientific  knowledge 
advanced,  however,  and  it  gradually  became  apparent  that  true 
progress  was  to  be  made  only,  or  mainly,  by  actual  observation  and 
experiment,  the  laboratory  became  the  field  of  work,  and  there 
gradually  came  full  recognition  of  the  necessity  for  practical  study 
of  the  many  questions  that  were  constantly  arising  for  settlement. 
No  longer  satisfied  by  the  dogmatic  statements  of  the  earlier  writers, 
thoughtful  people  began  to  ask  for  facts  and  demonstration,  and  the 
laboratory  and  its  facilities  grew  side  by  side  with  a  growing  craving 
