582  Therapeutic  Application  of  the  X.Rays.  {^SS^SSt 
mental  work  and  honest  scientific  investigation  must  be  done  before 
it  can  be  said  definitely  what  can  and  what  cannot  be  done  by- 
means  of  the  X-rays.  In  the  meantime  we  must  not  forget  that 
these  rays  are  active  agents,  and  like  all  active  agents  for  possible 
good,  are  also  capable  of  doing  harm  in  the  hands  of  the  inexperi- 
enced or  careless. 
It  goes  without  saying  that  an  agent  that  is  powerful  enough  to 
effect  a  change  in  a  chronic,  abnormal  condition  that  has  refused  to 
yield  to  other  treatment,  is  also  powerful  enough  to  cause  damage 
in  normal  structures  when  improperly  used.  In  this  connection  it 
may  be  well  to  call  attention  to  a  paper  published  in  a  recent 
number  of  the  Philadelphia  Medical  Journal  by  Dr.  Codman,  of 
Boston,  in  which  he  has  collected  data  of  upwards  of  200  cases  of 
so-called  X-ray  burns, .  and  shows  that  a  very  large  percentage  of 
these  cases  were  caused  by  either  carelessness  in  the  technic  or 
by  persons  ignorant  of  the  necessary  precautions  that  should  be 
taken. 
In  addition  to  the  conditions  that  have  been  enumerated  above, 
the  X-rays  have  been  used  as  a  cosmetic  agent  to  remove  super- 
fluous hair;  in  some  cases  of  psoriasis,  eczema  and  acne  they  have 
also  given  very  favorable  results.  Altogether,  it  may  be  said  that 
this  mode  of  treatment  is  much  more  applicable  in  the  various 
affections  of  the  skin  than  in  cases  where  the  deeper  tissues  are 
involved,  though  a  number  of  cases  have  been  reported  where  en- 
larged glands  have  resolved  themselves  and  disappeared  without 
the  use  of  any  other  therapeutic  agent. 
In  addition  to  the  curative  action,  the  X-rays  also  have  a  marked 
analgesic  or  anodyne  effect ;  this  property  has  been  noticed  by  many, 
and  usually  manifests  itself  in  cases  that  have  been  exposed  to  the 
action  of  the  X-rays  for  some  time  or  repeatedly.  By  some,  this 
anodyne  effect  of  the  X-rays  is  supposed  to  be  purely  mental ;  and 
while  this  may  be  true  in  some  cases  it  does  not  explain  why  a 
patient  is  at  times  entirely  relieved  of  pain  for  a  considerable  length 
of  time  after  a  prolonged  exposure  to  these  rays. 
To  sum  up  our  present  knowledge  on  the  subject,  we  may  say 
that,  while  a  considerable  amount  of  valuable  data  is  available,  there 
is  no  satisfactory  basis  on  which  we  can  estimate  definitely  the 
amount  of  exposure  that  will  be  required  to  bring  about  a  certain 
curative  effect.    The  factors  entering  into  a  computation  of  this 
