314 Dr. Pearson on expectorated Matter. 
natural science, and important practical information to the 
Physician. 
On the present occasion, I desire the honour of communi- 
cating the knowledge I may have acquired, by investigating 
the properties of expectorated matter secreted by the bron- 
chial membrane. The appearances of this substance serve to 
regulate the judgment of the Physician concerning several dis- 
eases of the lungs ; but especially of that of pulmonary tubercles 
which yearly destroys igo,ooo to 140,000 subjects of the 
United Kingdom. It is lit that I remark, that I do not notice 
in this paper the ingenious experiments of several learned 
Chemists, because by so doing I should be led into a detail of 
too great extent for my design. 
The numerous varieties of expectorated matter, according 
to my observation, may be arranged and characterized under 
the following seven heads : 
I. The jelly-like semi-transparent kind of a bluish hue, ex- 
creted in the healthy state. 
II. The thin mucilage-like transparent matter, so copiously 
expectorated in bronchial catarrhs. 
III. The thick opaque straw coloured, or white and very 
tenacious matter, coughed up in a great variety of bronchial 
and pulmonary affections ; especialty in that of tubercles. 
IV. Puriform matter secreted without any division of con- 
tinuity, or breach of surface of the bronchial membrane, very 
commonly occurring in pulmonary consumptions. 
V. The matter which consists of opaque viscid masses, to- 
gether with transparent fluid ; or the second sort above stated, 
with nodules of the third or fourth kind. 
