effects produced on the air cells of the lungsy &c. 305 
was familiar to him. The disease in all its stages must have 
been constantly under his eye in the numerous dead bodies 
with which the dissecting room was for twelve years, during 
which he taught anatomy, regularly suj 3 plied, and yet he 
neither had become acquainted with its origin nor its nature. 
He considers it to consist of white specks situated between 
the pleura and air cells, too small to admit of particular 
examination. 
In his Morbid Anatomy, his words are, Tubercles con- 
“ sist of rounded bodies of a white colour, interspersed 
“ through the substance of the lungs ; they are probably 
formed in the cellular structure which connects the air 
“ cells of the lungs together, and are not a morbid affection 
of glands, as has been frequently imagined. There is no 
“ glandular structure in the cellular connecting medium of 
“ the lungs ; on the inside of the bronchiee, continued from 
“ the trachea, where there are follicles, tubercles have never 
“ been seen. They are at first very small, not being larger 
** than the heads of very small pins, and in that case are 
“ frequently accumulated in small clusters. The smaller 
“ tubercles of a cluster grow probably together and form 
“ one large one. The more ordinary size of a tubercle is 
“ about that of a garden pea, but they are subject in that 
“ respect to great variety ; they adhere closely to the sub- 
“ stance of the lungs, but have no particular covering, or 
“ capsule, and have little or no vascularity ; when cut into, 
“ they are found to consist of a white smooth substance 
“ having a firm texture, and often contain in parts a thick 
“ curdly pus.’’ Dr. Baillie has given two plates, in each 
of which there are two figures. In the first, the tubercles 
MDcccxxvn. R r 
