476 
CONGRESS ON TUBERCULOSIS. 
io per cent, and 5 per cent., and sometimes even when weaker 
than that. 
So that every suspected animal which clears with 10 per 
cent, serum, a culture that would be imperfectly cleared with 
20 per cent, serum from a healthy animal, may be considered as 
affected by tuberculosis. 
4. A diagnostic injection of tuberculin (injection revelatrice 
de tuberculine) does not perceptibly modify the agglutinating 
power of healthy cattle (bovine). 
5. Serum-agglutination is therefore a new method of diag¬ 
nosing tuberculosis in oxen, which can be utilized under any 
conditions ad hoc , especially in cases where recourse cannot be 
had to the use of tuberculin. 
PROF. KOCH MAKES A STATEMENT—“EXPERIMENT 
NOT ARGUMENT.” 
Berlin, Aug. 16. —Professor Robert Koch, in a signed state¬ 
ment, to-day says :— 
u Experiment and not argument must be the watchword of 
medical and scientific men who would fight consumption to the 
•finish. I deprecate very deeply—though not from a personal, 
standpoint, but from the standpoint of the vital issues involved 
—that theories, by whomsoever advanced, should now sow only 
greater discord in our already many-minded ranks. We are 
well on the road to victory over consumption. The final tri¬ 
umph is denied only by those who are unwilling to sacrifice 
their hobbies and work together to the common end. 
“ I have one word and only one word to say, and that is what 
I said in Eondon. That word is ‘ experiment.’ I would send 
it to my brother practitioners the world over. The time has 
passed when we may be guided either with certainty or profit 
by statistics. Nothing short of actual dealing with actual con¬ 
ditions will avail. We demonstrated that human tuberculosis 
was incapable of transmission to cattle. 
“ We have now to lend ourselves to the reverse proposition. 
We cannot, of course, experiment with human beings or infect 
them. Therefore it is necessary to keep a rigid lookout on all 
suspicions cases of what seems to be natural infection with 
cattle tuberculosis, and in this way proceed to determine if such 
cases really come from cattle disease or from human disease. 
We must continue such experiments unceasingly. 
u Here in Berlin the Prussian institute for infectious disease 
has already made arrangement for experiments on an extensive 
