HALL, ON THORACIC CONSUMPIION. 163 



coudition, infiltrates the tissue. Tlie elements of tubercle, according to 

 Wedl, Yogel, Lebert, Gluge, Rokitausky, and as far as my own observations 

 enable me to judge, may be described as — 



" {a) Molecules, assembled in superimposed layers, some too minute to 



be measured. 

 " {b) Flocculent masses, consisting of proteine bodies, only seen when the 



tubercle is carefully spread out. 

 " {c) Hounded or oval nuclei, imbedded in a hyalira matrix, with 



scattered molecules, 

 "(fif) Flattened angular, granular corpuscles, rarely with a distinct 



nucleus, which become transparent on the addition of acetic acid. 

 " {e) Cells, occasionally elongated, with distinct nuclei. 



" Oral/ tubercle is of uniform consistence, toughish or soft, compressible, 

 and of a pearly gray colour; it is composed essentially of 'a basis substance, 

 which is solid and homogeneous, and serves as the uniting medium of certain 

 corpuscular elements ;' such as oily-looking granules, nuclei, and a few cells ; 

 the elements of the tissue in which it is deposited may also frequently be 

 seen. I have never discovered any vessel in separate tubercles, although 

 ■when several are aggregated together, in the interspaces some traces of those 

 belonging to the tissue may be observed. 



" Yellow tubercle, which usually forms in larger masses than the gray, 

 varies in colour, though generally of a whitish-yellow hue. These tubercles 

 are from the first opaque, of a cheesy consistence, containing a large 

 abundance of fine proteine molecules, among which may be detected the 

 elements of gray tubercle, shrivelled, indented, and wrinkled, and of a 

 yellowish lustre. The relation of the two varieties of tubercle to each other 

 is a point of considerable interest ; and Laennec without doubt was right 

 when he taught that gray tubercle sooner or later is converted into yellow 

 tubercle. This undergoes two metamorphoses of very great importance to 

 tlie practising physician ; one is that of softening — the other that of cretif cation. 

 That yellow tubercle should be tlius regarded as a secondary form of gray 

 tubercle is generally correct, and also in strict accordance with the fatty 

 metamorphoses of normal and newly formed elements ; but it has been 

 suggested with some probability that the remains of the proteine compounds, 

 which have not been used in the formation of the organic elementary parts, 

 may at once undergo fatty degeneration ; and, consequently, that it is not 

 absolutely necessary that the yellow tubercle should have previously been of 

 the gray kind." 



Further on. Dr. Hall gives precise directions for ex- 

 amining the expectorated matter in cases of disease of the 

 lungs : 



" To form a correct opinion of the nature of the sputa submitted to us 

 for examination requires no little time and study. It obliges a thorough 

 knowledge of the appearances of the secretion natural to the mucous and 

 salivary glands, the epithelium of the mouth, of the fauces, and the pharynx, 

 and the results of the varied morbid processes which may take place in the 

 several parts. Portions of fungous vegetations, which are so frequently 

 present at the back of the mouth and in the matter secreted by the tonsils, 

 are very often seen in the expectoration, mingled with the remains of the 

 food that has been taken ; such as muscular fibre, starch, oil globules, 

 various vegetable and animal substances, &c. It must not, therefore, hastily 

 be concluded that everything we see in the sputa, under the microscope. 



