PRODUCTS, ADVENTITIOUS. 



105 



(2.) Infiltrated tubercle has been described 

 principally in the lung, and is here said to ex- 

 hibit two kinds of appearance ; (a) the grey, 

 and (b) the gelatiniform. () There are oc- 

 casionally found in the lungs irregular masses 

 of variable and, it may be, considerable size 

 (five inches in diameter even) of greyish semi- 

 transparent aspect, homogeneous, shining, and 

 without distinct structure ; such appearances 

 are generally seen towards the apex of the 

 organ, and may exist in very rare cases inde- 

 pendently of any acknowledged form of tuber- 

 culous deposit ; slices of texture thus affected 

 sink in water, are moist on the surface, dense, 

 and compact. In the midst of such masses it 

 is sufficiently usual to discover a number of 

 small specks of yellow opaque tuberculous 

 matter ; these increase in number and size, 

 and thereby gradually cause the disappear- 

 ance of the grey matter. Now it is admitted 

 on all hands that the characters of this alleged 

 tuberculous infiltration are extremely like 

 those of chronic pneumonia ; and in our mind 

 it is extremely doubtful whether the morbid 

 state be anything more than a particular form 

 of that inflammation. M. Louis draws at- 

 tention to the following points as distinctive 

 of chronic pneumonic induration: 1. Instead 

 of being transparent, the affected tissue is 

 opaque ; 2. instead of being homogeneous, it 

 is traversed by thick white septa ; 3. the in- 

 durated parts are more compact than in the 

 presumed tuberculous infiltration. But in ac- 

 knowledged chronic pneumonia all these cha- 

 racters are subject to a great variation in 

 amount; and the formation of yellow tu- 

 bercle proves nothing in either direction, as 

 there is no reason why such formation should 

 not occur in a tissue infiltrated with indu- 

 ration-matter. (b~) Of the gelatiniform tuber- 

 culous infiltration of Laennec, it is sufficient 

 to say that no doubt can be entertained as 

 to the fact of his having described, under 

 this name, infiltration of common exudation 

 matter with excess of serosity, sanguineous 

 or not. Tubercle does, however, occur in the 

 endosteal texture of bone in the infiltrated 

 form. 



The microscopical constitution of yellow 

 tubercle may be described as follows, at least 

 according to the observations we have our- 

 selves made. (1.) Granular substance exists 

 in abundance in tuberculous matter ; large 

 masses of soft consistence sometimes consist 

 almost solely of it ; and, as the process of 

 softening advances, it abounds likewise; when 

 of well-defined characters and abundant, it 

 constitutes a very distinctive element of tu- 

 bercle. The granules are dark, of yellowish 

 brown tint, heaped up in masses, varying in 

 size from about 1-ith or I -oth of that of the 

 red blood corpuscle (say it%oo or TSWOO of an 

 inch) to the merest points. Some of them, 

 undissolved by acids, alkalies, or ether, are of 

 modified protein-basis ; others, soluble in hot 

 ether, are of fatty nature : the latter are 

 sometimes, though rarely, absent altogether. 

 (2.) Cells. Cells, though probably always ex- 

 istent in tubercle at some stage of its develop- 



ment, are not always to be found, or to be found 

 in very minute proportion only, in specimens 

 examined. In some cases they apparently con- 

 stitute the entire tuberculous mass. We have 

 found them sometimes of circular form, and 

 rather flatfish ; sometimes irregular in shape 

 and with rounded angles, never caudate, and 

 nearly averaging in size that of the white blood- 

 corpuscle. They contain a variable number of 

 granules scattered without order through their 

 substance, but generally leaving a free circlet 

 at the periphery. We have never seen a dis- 

 tinctly defined nucleus within them ; acetic 

 acid simply renders the cell-wall more trans- 

 parent, and exhibits the granules more clearly. 

 (3.) Irregular particles. Shapeless particles, 

 flat, pale, and on an average of less size than 

 the cells, are sometimes seen. These are pro- 

 bably, in part at least, the walls of disinte- 

 grating cells ; whether they eventually go to 

 form granular matter is a point open to 

 inquiry, but appears to us probable. With 

 these the substantial constituents of tubercle, 

 are sometimes accidentally associated. (4.) 

 large fat globules; (5.) plates of cholesterin ; 

 (6.) amorphous saline particles; (7.) melanic 

 cells and granules. 



Nothing having the attributes of a stromacan 

 be detected in tuberculous matter; but a semi- 

 transparent substance, more or less solid, slowly 

 soluble in acetic acid, absolutely structureless 

 and amorphous, holds its elements together. 

 Neither does tubercle ever contain vessels of 

 new formation ; and the imprisonment by tu- 

 berculous deposit of natural capillary vessels, 

 still pervious, is comparatively rare and acci- 

 dental ; there is a tendenc}', constant in action, 

 and eventually irresistible, to obliteration of the 

 vessels around and amid which the blastema 

 of tubercle is thrown out. A new vascular 

 system, we are aware, has been found to 

 originate in the vicinity of tubercle ; but this 

 development takes place within common in- 

 flammatory exudation matter. In the same 

 way there may be found on the confines of 

 tuberculous matter compound granule-cor- 

 puscles, pus-corpuscles, with, of course, the 

 ultimate elements of the tissues implicated. 



In the same natural texture with such tuber- 

 culous matter as we have now described, are 

 very frequently found certain small bodies vary- 

 ing in size from that of a pin's head to a very 

 small pea, of greyish-white or greyish tint and 

 glistening aspect. These bodies are known as 

 the semi-transjjarcnt grey granulation ; and 

 their affinities to yellow tuberculous matter 

 have been a theme of constant disputation 

 from the period at which tubercle first became 

 the subject of close study. While some regard 

 them as products of common inflammation 

 (Schroeder van der Kolk, Andral) ; while 

 visionaries are found (Kuhn*) to maintain 

 that their relationship is closest to the Nema- 

 zoa of Gaillou (a class of beings forming a link 

 between vegetable and animal existences) ; 

 while a reasoner habitually most cautious 

 (Carswell) regards them in some situations 

 the lung as an admixture of mucus and true 

 * Gaz. Jle'd. de Paris, t. ii. p. 342. 1834. 



