58 
EDITORIAL OBSERVATIONS. 
something tragic in the idea of well-meaning people delibe- 
rately entangling themselves in confusion of the most hope- 
less character. Take the last suggested experiments as a 
type of the practical idea. The mere act of holding back 
until another attack occurs, faithfully expresses a conviction 
of the probability, or at least of the possibility of no more 
attacks in the herd, and yet, if one other animal be attacked 
and inoculation be then had recourse to, what is likely to 
happen ? If none of the inoculated animals are attacked, 
what a testimony to the efficacy of inoculation ! And yet 
in numerous instances the same result has followed the 
adoption of sanitary measures, the use of disinfectants, and 
it must also be confessed the “ let-alone system.” 
In 1850 we were called upon to advise respecting the 
treatment of a number of cattle — Irish, Scotch, and Here- 
ford — among which pleuro-pneumonia had made rather 
serious ravages ; twenty-four animals having died out of 200. 
Various means of a sanitary character were employed, and 
judging from the result, they were completely successful, as 
no more cases occurred in the herd. 
Recently an outbreak of pleuro-pneumonia occurred in 
a small herd of ten or twelve cattle ; disinfection was re- 
sorted to, and the sick animals were removed from the 
apparently healthy. The disease, after attacking three 
animals, which died, ceased altogether, and has not since 
reappeared. These instances are only quoted in exempli- 
fication of the difficulty to which we have alluded, of 
distinguishing between post hoc and propter hoc ; and it 
is to be feared that the difficulty will not be lessened by 
the prosecution of the inquiry according to the method which 
is being adopted If inoculation had been employed in the 
few instances referred to, and in numerous other cases 
which we can call to mind, a very strong argument would 
have been established in its favour ; but while it is ad- 
mitted that inoculated animals are at least sometimes 
attacked while others escape, and that the progress of the 
disease is arrested by other means, we cannot avoid the 
conclusion, that a repetition of former experiments is 
likely to lead to more contradictions. 
If the farmers of England have made up their minds to 
