212 
C. J. SIHLER. 
TUBERCULOSIS. 
By De. C. J. Sihlee, Kansas City, Kas.* 
This is a specific infectious disease, produced by tubercles, 
which are in turn special products of a distinct micro-organism, 
known as the Bacillus tuberculosis. The actual or continued 
presence of tubercles is, however, not a necessary factor in 
the production, course or development of tuberculosis. 
Preexisting tubercles may have been discharged, or after 
softening become calcified or absorbed. In acute tuberculosis, 
it is not uncommon to find the spleen enlarged but free from 
tuberculous deposit. 
The history of tuberculosis falls into five periods, three of 
which at least are quite distinct, in that they date from the 
discoveries of distinct individuals, Bayle and Laennec, Villemin 
and Koch. 
The first is the period of ancient history. During all this 
period the disease was observed from a clinical stand point 
only. 
The second period, beginning with the birth of anatomy, 
in the sixteenth century, furnishes the first definite knowledge 
regarding changes of lesions of structure. 
The third period, following the publications of Bayle and 
Laennec, in the first quarter of the nineteenth century, declar¬ 
ing tuberculosis a separate affection, due to the deposit oj 
tubercle, a specific product independent of ordinary inflam¬ 
mation. 
The fourth period was introduced late in th$ last half ol 
the nineteenth century, with the inoculation experiments ol 
Villemin, in 1865 ; and the fifth was announced with the 
brilliant revelations of Koch, in 1882. 
There is but one form of tuberculosis, and scrofula is onl} 
an external form of it. Villemin concludes tuberculosis is a 
specific disease. It belongs, therefore, among the viruleni 
affections, and takes its places in nosology with small-pox. 
scarlet fever, syphilis, and more specially with glanders. Tht 
* From the Report of the Kansas State Board of Agriculture. 
