108 



PRODUCTS, ADVENTITIOUS. 



factory. Our own belief (which is firm) in its 

 occurrence rests upon the following facts and 

 arguments. 1 . Rabbits submitted to influences 

 which, experience has proved, unfailingly lead 

 to the development of tubercle in the liver and 

 elsewhere, have subsequently been placed in 

 conditions favourable to health, eventually been 

 killed, and no traces, or the merest traces, of 

 tubercle been discovered in their bodies. (Jen- 

 ner, Baron, Carswell.) 2. Miliary tubercles, 

 developed in the substance of pleural or peri- 

 toneal false membrane, disappear in cases 

 where the latter becomes cellulo-serous in 

 texture. 3. Tuberculous matter disappears 

 from the substance of enlarged strumous 

 glands. 4. We have seen and satisfactorily 

 observed cases of tuberculization of the bron- 

 chial glands in children, in which (while the 

 local and general symptoms of phthisis were 

 fully developed, and the physical signs of 

 marked enlargement of the bronchial glands 

 were no less distinct) recovery in respect of 

 symptoms has occurred, coevally with modi- 

 fication and ultimately disappearance of those 

 physical signs. Such cases are unfortunately 

 rare. 5. And, again, we have found the phy- 

 sical signs of induration at the apex of a 

 lung in persons labouring under the local and 

 general symptoms of phthisis, and belonging to 

 a tainted family ; and these signs have totally 

 disappeared in company with the train of local 

 and general symptoms. The event is, no 

 doubt, singularly rare ; and the disappearance 

 of induration-signs may, by the sceptical, be 

 referred to the cessation of congestion. But 

 congestion has its special signs, which were 

 riot present in the cases we refer to ; and con- 

 gestion at the apex is, in the very great ma- 

 jority of cases, of tuberculous origin. 6. 

 Andral and Reynaud attempt to trace certain 

 furrowed and excavated appearances of pul- 

 monary tubercles to a process of absorption, 



but they do this dubitatively, and the point 



has not been investigated by others. 



(b.) Of the removal by absorption of the 

 animal ingredients of tubercle, while saline 

 particles are deposited in abundance (so- 

 called "transformation"), no doubt can be 

 entertained. The gradual change of the tuber- 

 culous matter may be traced from a condition 

 of mere desiccation with greasiness to the feel, 

 to that of osteo-petrous substance. The traces 

 of animal material may eventually almost 

 wholly, if not wholly, disappear ; for Thenard 

 found that while " crude" tubercle contained 

 98.15 per cent, of animal and 1.85 of saline 

 matters, cretaceous tubercle furnished but 3.0 

 per cent, of the former and 96.0 of the latter. 



The production of this change in tubercu- 

 lous matter is very frequently (but certainly 

 not always witness the case of the mesen- 

 teric glands) connected with the presence of 

 common plastic exudation in the surrounding 

 natural texture. This exudation-matter gra- 

 dually hardens, eventually assuming the fibrous 

 condition, and possessed (like all similar exu- 

 dation) of strong contractile properties, pro- 

 bably facilitates the absorption of the enclosed 

 tubercle by the pressure it exercises. 



But absorption may proceed further. The 

 cretaceous, calcareous, or osteo-petrous sub- 

 stances, representatives of bygone tubercle, 

 sometimes totally disappear; and, at a later pe- 

 riod still, the plastic fibrinous substance is itself 

 removed. The part where all these changes 

 have occurred (in the lungs for example) may 

 even appear healthy; but on close examination 

 puckering (parenchymatous, we mean, not 

 pleural) is discovered in a spot, where oblite- 

 rated vessels and bronchial tubes converge, 

 as the indelible evidence of the morbid con- 

 ditions that have preceded. This puckering 

 and obliteration have (as we believe errone- 

 ously) been ascribed to the cicatrization of 

 cavities. 



(e.) The elimination of tuberculous matter 

 by excretion is effected from free surfaces, or 

 from the stroma of parts and organs. 



1. Excretion of tuberculous matter, without 

 breach of surface in the part supplying it, oc- 

 curs in the uterine, renal, and pulmonary pas- 

 sages, never, so far as we have ourselves 

 observed, in the intestines. The occurrence 

 is, under all circumstances, rare. 



2. The elimination of tubercle from the 

 stroma of parts involves the destruction of 

 tissue by an ulcerative or gangrenous process. 

 Such elimination takes place either when the 

 cretaceous change has occurred, or independ- 

 ently of any such change. Of the former (the 

 rarer of the two) the escape of cretaceous 

 masses from the bronchial glands through an 

 ulcerated opening in the trachea, furnishes a 

 striking example ; the expectoration of such 

 masses from the lungs themselves is extremely 

 rare, while, on the other hand, these organs 

 supply the most important illustration of eli- 

 mination of unchanged tuberculous substance. 



Softening of tuberculous matter being com- 

 plete,the natural textures contained within the 

 area occupied by that matter have likewise lost 

 their consistence, as a result of infiltration with 

 morbid fluids and of imperfect nutrition. Ulcer- 

 ative destruction readily sets in; minute bron- 

 chial tubes are in consequence opened ; through 

 these the softened matter and (as is proved by 

 microscopical examination) fragments of the 

 parenchymatous fibrils and capillaries of the 

 lung are evacuated. An excavation (cavity or 

 cavern) in the pulmonary substance is the 

 result. 



When a cavity is of recent date, its walls, 

 smooth and even, are commonly lined, more or 

 less completely, with plastic exudation, fragile, 

 whitish, and opaque ; but the pulmonary tissue 

 is in some instances bare and unprotected. The 

 walls of cavities of old date, firm and resisting, 

 are lined with a membrane, divisible into two 

 strata the external dense, greyish, and fibrous, 

 the internal soft and velvety, deposited conti- 

 nuously or in patches on the inner surface of 

 the former. Or (as existed in one-fourth of 

 the old cavities examined by Louis) the walls 

 may be totally free from any membranous in- 

 vestment. The walls are uneven, irregular, 

 and coated commonly by bands composed of 

 pulmonary substance (rarely containing per- 

 meable vessels) studded with tuberculous 



