.ETIOLOGY OF TUBERCULOSIS. 
115 
ten tuberculous affections of the bone, thus divided: three times on wrist bones, 
five times on ankle bones, twice vortex caries (of these last in one case only the 
pus was examined). To a great extent I owe this material for examination to 
Privy Councillor Bardeleben. 
The granulation-tissue which is formed in the surroundings of tuberculous 
joints and bones offers no essential difference in the single cases. The same 
appearances repeat themselves constantly in the structure of the tissue and in 
the arrangement of the bacilli, and resemble completely the description given 
of scrofulous glands. One finds just the same more or less scattered and often 
confluent herds of epithelioid cells which surround giant cells, and also here 
the occurrence of bacilli is confined almost exclusively to the giant cells. In 
the caseous, nucleusless spots, as well as in the pus secretions, the attempts to 
find scattered bacilli only succeeded in some cases. Also in this respect tu¬ 
berculosis of the bones and joints conducts iiself exactly like that of the scrofu¬ 
lous glands. 
The bacilli could be proved in all the cases. Only in the abscess pus coming 
from the vortex caries was it impossible to find tuberculous bacilli. But in¬ 
oculation with this pus, as was formerly mentioned of the pus of a tuberculous 
abscess of the kidneys, gave a positive result. 
✓ 
6.—Lupus. 
According to the anatomical investigations of Friedlaender and the positive 
results of inoculation which Hiiter and Schuller have obtained, it was to be 
expected that lupus must also belong to the group of genuine tnberculous 
diseases. I therefore used the opportunity offered to me by Director Hahn, 
Prof. Kuster and Prof. Lewin, soon after the publication of my first comniu- 
nication*concerning the aetiology of tuberculosis, to examine a nnmber of cases 
of lupus in order to gain certainty in regard to this supposition. 
Seven cases of lupus were investigated, which all had the most decided 
symptoms and were watched for a long time in the hospital, so that no doubt 
of the correctness of the diagnosis can be entertained. From four cases I 
received excised pieces of the skin, from the other three cases lupus substance 
scraped out. For direct microscopic examination only the excised pieces of 
skin were suitable. In all four cases, though only a few specimens in each, 
tuberculous were found, only, however, in the interior of giant cells. The 
tuberculous bacilli are so scattered in the lupus tissue that in two cases the bacilli 
were not found until from one twenty-seven sections, from the other forty-three 
sections had been examined. Nevertheless, it happened repeatedly that when 
in a succession of sections not a single bacillus showed itself, sections followed 
each other quickly with from 1—3 bacilli. More than one bacillus I have never 
seen in a giant cell in lupus. 
It may for the present be remarked here that of all the seven cases, inoc¬ 
ulations were made into the anterior eye-chambers of rabbits, which without 
exception produced tuberculosis of the iris, and in those animals which were 
allowed to live for a longer time, general tuberculosis. In these tubercles re¬ 
sulting from inoculation numerous tuberculous bacilli were found. From one 
case (excised piece of skin from the cheek of a ten-year-old boy suffering from 
