Krro7's  in  the  Tuherctdin  Test. 
243 
which,  mainly  at  the  instigation  of  Professor  Koch,  was 
api)ointed  to  investigate  experimentally  the  question  so  hotly 
discussed  at  the  British  Congress  on  Tuberculosis  in  1901,  viz., 
whether  human  and  bovine  tuberculosis  are  identical  diseases. 
At  the  Congress  in  question  Professor  Koch  had  maintained 
that  the  two  diseases  were  different,  and  had  also  expressed 
himself  in  terms  which  seemed  to  indicate  that  in  his  opinion 
the  bovine  disease  was  not  transmissible  to  human  beings. 
The  experiments  of  the  German  Commission  referred  to  above 
yielded  results  which  made  it  impossible  to  hold  that  view, 
since  in  four  cases  of  human  tuberculosis,  out  of  a total  of  forty 
examined,  the  lesions  were  found  to  contain  bacilli  which 
were  capable  of  infecting  cattle  with  tuberculosis,  and  had, 
according  to  Professor  Koch’s  own  dictum,  to  be  regarded  as 
the  bacilli  of  bovine  tuberculosis. 
During  the  course  of  the  past  year  the  Royal  Commission 
on  Tuberculosis,  which  was  appointed  in  1901  to  investigate 
the  same  question,  issued  an  interim  report,  in  which  it  is 
stated  that  at  the  date  of  the  report  the  Commission  had 
investigated  over  twenty  cases  of  human  tuberculosis,  and  had 
in  seven  of  these  found  that  the  bacilli  present  in  the  human 
lesions  were  immediately  capable  of  infecting  cattle  with  an 
acute  form  of  the  disease.  If  one  admits  the  soundness  of 
Professor  Koch’s  reasoning,  in  these  seven  cases  of  human 
tuberculosis  the  patients  must  have  been  infected  with  the 
bovine  disease.  The  reports  of  the  German  and  British  Com- 
missions ai’e  thus  in  agreement,  except  that  the  latter  found 
that  the  human  disease  was  transmissible  to  cattle  in  a larger 
proportion  of  cases. 
Perhaps  one  might  say  that  the  two  Commissions  appear  to 
be  in  agreement  with  regard  to  the  main  point,  which  is  that 
human  beings  may  become  infected  with  the  bacilli  which  are 
the  cause  of  tuberculosis  in  cattle.  Precisely  how  frequently 
this  transmission  of  the  disease  from  cattle  to  man  occurs  is 
still  a matter  of  dispute,  and  it  may  be  a very  long  time  before 
there  is  anything  like  general  agreement  with  regard  to  that 
point. 
Errors  in  the  Tuberculin  Test. 
The  reliability  of  the  tuberculin  test,  when  carried  out 
under  what  may  be  called  proper  conditions,  is  now  universally 
recognised.  The  most  important  of  these  conditions  ai'e 
(1)  that  the  cattle  to  be  tested  should  be  standing  undisturbed 
in  premises  to  which  they  have  become  accustomed  ; (2)  that 
they  are  in  apparent  health,  or  at  least  not  suffering  from 
anything  which  renders  their  temperature  high  or  unsteady  ; 
and  (3)  that  they  have  not  recently  been  tested  with  tuber- 
culin. It  has  hitherto  been  customary  to  insist  upon  the  last 
K 2 
