549 
DISCOVERY OF THE GERM OF SWINE-PLAGUE. 
gations were not sufficient to show that this parasite was the 
cause of the disease. The fact that from later observations, of 
an entirely different nature, he attributed the cause to another 
organism, surely can at this day detract nothing from the merits 
of the paper from which I have just quoted; and it must conse¬ 
quently be acknowledged as a matter of historical truth, the data 
of which are fully recorded, that Klein discovered the micrococci 
of swine-plague long before they were seen by Pasteur and 
Thuillier. 
We can now pass to a brief consideration of the investigations 
which were intended to connect certain organisms found in the 
tissues or liquids of diseased and dead animals with the cause of 
the disease. 
In 1878 a second and very elaborate report was made by Dr. 
Klein, * in which he gives experiments that are supposed to de¬ 
monstrate the pathogenic nature of a specific bacillus found in 
certain liquids of diseased hogs, and cultivated for several gene¬ 
rations in the aqueous humor from rabbit’s eyes. Coming so soon 
after the publication of Koch’s remarkable studies of the life- 
history of the anthrax bacillus, and agreeing so closely with them 
in all important respects, it is scarcely to be doubted that the 
earlier conclusions had more or less influence in shaping the later 
ones. While it might be interesting to the specialist to enter 
into details in regard to the defective methods of cultivation 
used, the unsatisfactory results of the microscopic examination of 
the tissues and fresh liquids for the bacilli, and the still more un¬ 
satisfactory results of the inoculation experiments with the culti¬ 
vated organisms, our space will not permit this at present. In 
behalf of a most indefatigable worker, however, I would call 
attention to the fact that this mistake of Klein’s was not so extra¬ 
ordinary as it may appear to many to-day, because the methods of 
cultivating and studying disease-germs have to a large extent been 
perfected since that time. 
In the same year a number of persons were appointed by the 
* Report on infectious pneumo-enteritis of the pig (so-called pig-typhoid;, by 
Dr. E. Klein, F.R.S. Report of the medical officer of the local government 
board. London, 1877 and 1878, pp. 169-290. 
