﻿COMMISSIOKER 
  OF 
  AGRICULTURE. 
  54:3 
  

  

  fail 
  to 
  react 
  to 
  the 
  following 
  one." 
  Pearson 
  believes 
  tliat 
  tliis 
  

   represents 
  about 
  the 
  true 
  proportions. 
  The 
  records 
  available 
  indi- 
  

   cate 
  that 
  a 
  10 
  per 
  cent, 
  failure 
  on 
  second 
  test 
  is 
  someAvhat 
  high. 
  

   It 
  has 
  been 
  quite 
  clearly 
  shown, 
  however, 
  that 
  by 
  increasing 
  the 
  

   size 
  of 
  the 
  dose, 
  which 
  can 
  be 
  done 
  with 
  impunity, 
  the 
  resulting 
  

   resistance 
  from 
  a 
  single 
  dose 
  can 
  be 
  overcome.^^ 
  It 
  is 
  possible 
  that 
  

   rarely 
  a 
  tuberculous 
  animal 
  could 
  escape 
  under 
  such 
  a 
  temporary 
  

   immunity; 
  but 
  if 
  a 
  second 
  test 
  was 
  applied 
  a 
  few 
  weeks 
  later 
  the 
  

   purchaser 
  could 
  be 
  reasonably 
  assured 
  against 
  the 
  disease. 
  

  

  The 
  value 
  of 
  tuberculin 
  is 
  now 
  no 
  longer 
  questioned 
  by 
  those 
  who 
  

   have 
  come 
  to 
  a 
  knowledge 
  of 
  its 
  searching 
  diagnostic 
  powers 
  and 
  

   harmlessness 
  to 
  healthy 
  and 
  diseased 
  animals. 
  The 
  cattle 
  owners 
  

   who, 
  through* 
  their 
  veterinarians, 
  have 
  used 
  it 
  privately 
  and 
  who 
  

   would 
  bear 
  witness 
  to 
  this 
  statement 
  are 
  very 
  numerous. 
  In 
  the 
  

   State 
  of 
  Pennsylvania, 
  where 
  the 
  percentage 
  of 
  tuberculous 
  cattle 
  

   in 
  infected 
  herds 
  has 
  been 
  reduced 
  during 
  the 
  last 
  few^ 
  years 
  from 
  

   25 
  to 
  11.6 
  per 
  cent.,^'^ 
  and 
  w^here 
  within 
  a 
  month 
  the 
  people 
  have 
  

   demanded 
  the 
  reappointment 
  of 
  a 
  veterinarian 
  w^ho 
  has 
  had 
  the 
  

   work 
  in 
  charge, 
  the 
  official 
  application 
  of 
  tuberculin 
  has 
  been 
  re- 
  

   stricted 
  to 
  those 
  wh'o 
  have 
  been 
  instructed 
  and 
  found 
  to 
  be 
  qualified 
  

   to 
  use 
  it. 
  This 
  fact 
  bears 
  evidence 
  for 
  the 
  theory 
  that 
  in 
  order 
  

   to 
  reduce 
  the 
  present 
  en-ors 
  of 
  5 
  or 
  perhaps 
  10 
  per 
  cent, 
  to 
  a 
  mini- 
  

   mum, 
  efficient 
  tuberculin 
  must 
  be 
  administered 
  by 
  competent 
  and 
  

   honorable 
  people 
  only. 
  

  

  If 
  w^e 
  summarize 
  the 
  facts 
  as 
  they 
  are, 
  and 
  the 
  convictions 
  of 
  

   tL:ose 
  who 
  from 
  experience 
  have 
  a 
  right 
  to 
  express 
  themselves 
  on 
  

   this 
  important 
  topic, 
  we 
  tend 
  to 
  these 
  conclusions: 
  

  

  1. 
  That 
  properly 
  made 
  tuberculin, 
  scientifically 
  applied, 
  will 
  

   indicate 
  the 
  presence 
  of 
  active 
  tuberculous 
  lesions 
  in 
  practically 
  

   every 
  animal 
  where 
  the 
  disease 
  is 
  not 
  sufficiently 
  advanced 
  to 
  be 
  

   detected 
  on 
  physical 
  examination. 
  It 
  is 
  not 
  infallible, 
  but 
  posi- 
  

  

  iCRoux 
  and 
  Nocard 
  (Reoiieil 
  de 
  Med., 
  1891) 
  state 
  that 
  they 
  have 
  a 
  tubercu- 
  

   lin 
  which 
  will 
  give 
  reaction 
  almost 
  indefinitely. 
  They 
  have 
  not, 
  however, 
  de- 
  

   scribed 
  its 
  mothod 
  of 
  preparation. 
  

  

  17 
  Proceedings 
  of 
  the 
  American 
  Veterinary 
  Medical 
  Association, 
  1899. 
  

  

  