156 
mation extends. That they are micrococci was proved by their 
forming lumps of uniform granules; these lumps stain deep pur- 
ple-blue in haematoxylin, and are thus very conspicuous, and 
besides resist the action of caustic potash, with which all the 
rest of the tissue disappears. These heaps of micrococci in 
locality correspond to the papillae, and are on the surface of the 
scab, but underneath the covering epithelium, some parts of this 
having changed into a dry, hard, discolored mass, others con- 
taining larger or smaller vesicles filled with fluid.” 1 
In the examination of the respiratory organs we 
are given even stronger evidence for connecting 
these organisms with the cause of the disease. In 
the mucous membrane of the anterior surface of the 
epiglottis, which was only slightly inflamed in its sub- 
mucous tissue, he found — 
“Lymphatic vessels filled with micrococci. . .. In the infil- 
trated, firm, more or less disintegrating parts [of the lung] I find 
great masses of micrococci filling up capillaries and veins, and 
also contained in lymphatics around arteries.2 . . . The pleurais 
much swollen, and contains great numbers, continuous layers, of 
lumps of micrococci. The free surface of the membrane is in 
many parts covered with them. The exudation fluid is also 
charged with them as has been mentioned above.’ ® 
We have here the record of the unbiassed savant 
seeking after the truth, and describing what he sees 
without any attempt to draw conclusions or build up 
theories. It was before Koch’s brilliant investiga- 
tions, identifying the Bacillus anthracis as the active 
principle in charbon virus, had seen the light. There 
was still the greatest doubt as to whether the contagia 
were essentially animal cells, vegetable organisms, or 
chemical poisons. It would have been premature to 
have presented the micrococci at that time as the cause 
of the disease, though it is evident from these obser- 
vations that they existed in the tissues of the body 
before the death of the animal. We have conse- 
quently two questions to consider in an inquiry of 
this kind; viz., (1) Who is entitled to priority for 
discovering and demonstrating the presence of micro- 
cocci in the tissues and liquids of diseased animals? 
and (2) Who was first in proving the connection be- 
tween the micrococci and the essential constituent of 
the virus ? 
It seems very evident that Dr. Klein discovered the 
micrococci as early as 1876, but it is equally evident 
that his investigations were not sufficient to show 
that this parasite was the cause of the disease. The 
fact that from later observations, of an entirely differ- 
ent nature, le attributed the cause to another organ- 
ism, surely can at this day detract nothing from the 
merits of the paper from which I have just quoted; and 
it must consequently 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 
1 Loc. cit., p. 99. 2 Tbid., p. 100. 3 Tbid., p. 101. 
* 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. 
SCIENCE. 
Wyaeere =? 7) ee 
? 
[Vou. IIL, No. 53 
that are supposed to demonstrate the pathogenic na- 
ture of a specific bacillus found in certain liquids of 
diseased hogs, and cultivated for several generations 
in the aqueous humor from rabbits’ 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 re-— | 
spects, 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 defec- 
tive methods of cultivation used, the unsatisfactory 
results of the microscopic examination of the tissues 
-and fresh liquids for the bacilli, and the still more 
unsatisfactory results of the inoculation experiments 
with the cultivated organisms, our space will not per- 
mit 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 extraordinary 
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 ap- 
pointed by the U. S. commissioner of agriculture 
to investigate the disease known in this country as 
hog-cholera. The greater part of these served but 
two months; but Dr. Detmers, having reported the 
discovery of the disease-germ, was allowed to con- 
tinue his investigations. In his first report, Dr. Det- 
mers stated that the disease was caused by a bacillus, 
which he named Bacillus suis, because the same, so 
far as he was able to learn, was peculiar to and char- 
acteristic of swine-plague.! He saw micrococci, but 
regarded them as bacillus germs: indeed, he states 
that he constantly observed one of these under the 
microscope while it ‘‘ budded, and grew to double its 
length, in exactly two hours.”’ ? 5 
This report of Dr. Detmers; coming so soon after 
Klein’s, and attributing the virulence to a bacillus of 
substantially the same characters as that described by 
Klein, while the latter’s micrococci were made to do 
duty as bacillus germs, —a relation which had been 
previously ascribed to them by the medical officer in 
his ‘ preliminary note,’ though it was not suggested 
by the English investigator himself, —did much to 
confirm the bacillus theory, and to convince scien- 
tific men that the parasite of another contagious fever 
had actually been isolated, and its connection with 
the disease demonstrated. 
In January, 1880, M. Mégnin published the results 
of a microscopic examination of the blood in this 
disease, in which he described and figured a micrococ- 
cus.? This organism existed in single granules, and 
also in clusters and chains, and agreed so closely with 
one subsequently studied by me that I reproduced the 
drawings of it in connection with my report written 
the following December.? 
1 Department of agriculture. Special report, No. 12, 1879, © 
p. 42. 
2 Loe. cit., p. 53. 
3 Recueil de médecine vétérinaire, 1880, pp. 36, 37. 
4 Department of agriculture. 
81, plate IX. 
Special report, No. 34, pp. 80, 
