110 



PRODUCTS, ADVENTITIOUS. 



exists at the base of the lung, where cavities 

 are excessively rare ; that such puckering 

 is so common that, if it really signify closure 

 of cavities, this must be admitted to be an 

 every-day occurrence an admission to which 

 the laws of general pathology and special 

 clinical experience are equally opposed ; 

 that the alleged cicatrices are always (as in- 

 sisted upon by Laennec himself) either ac- 

 tually under, or only a line or two distant 

 from, the pulmonary surface, whereas cavi- 

 ties are frequently seated deeply in the lung ; 

 that Laennec's clinical evidence in support 

 of closure of cavities is exceedingly defec- 

 tive, and that were cicatrization so common, 

 as on his principles it must be, the oppor- 

 tunity of tracing the progress of contraction 

 during life would frequently occur, whereas it 

 has certainly never yet occurred to ourselves, 

 nor (so far as we are aware) as matter capable 

 of demonstration to any one else. 



Laennec's anatomical facts were correctly 

 observed, but he misinterpreted them patho- 

 logically. The cellulo-fibrous bands or no- 

 dules he noticed appear, in truth, to be formed 

 in either of the three following ways. (1.) 

 They are primary productions, generated 

 quite independently of tuberculization ; re- 

 sults of local inflammation perfectly assimi- 

 lable to the bands permeating more or less 

 completely the entire substance of the lung, 

 in certain cases of general chronic sub-inflam- 

 mation of the organ. (2.) They are produced 

 in the manner already explained (p. 108), in 

 connection with tubercle undergoing absorp- 

 tion. (3.) They are altogether extra-pul- 

 monary productions, and their apparent posi- 

 tion within the parenchyma of the lung, a 

 fallacy more or less easily exposed. 



Under all these circumstances their alleged 

 direct relationship to cavities is matter of 

 pure imagination ; but the last mentioned con- 

 dition of things only (which has been in- 

 sisted on principally by M. Fournet), needs to 

 be dwelt upon here. 



As a preliminary point, let it be observed 

 that viscera invested with serous membrane 

 are liable to undergo indentation by the con- 

 traction, and in the site, of plastic exudation. 

 Even the liver, dense as it is, we have occa- 

 sionally seen pretty deeply indentated in this 

 manner ; more frequently is this observed in 

 the spleen, but still more so (obviously from 

 the yielding character of its texture) in the 

 lung. Now, in the particular cases we have 

 in view, the following points may be traced. 

 1. Pleurisy occurs, local or general, with or 

 without liquid effusion. 2. The resulting 

 plastic exudation penetrates or not into sulci 

 on the pulmonary surface formed by creas- 

 ing ; these sulci are deeper if liquid effusion 

 has occurred, than under the contrary circum- 

 stances. 3. The plastic exudation is thicker 

 at some points than others, and there excess 

 of depression takes place, because its own 

 contractile force, and the force resisting at- 

 mospheric (excentric) pressure, are both 

 greatest there. 4. Processes from this super- 

 ficial exudation penetrate into the sulci (we 



have seen them three quarters of an inch 

 long). 5. The thinner peripheral portion of 

 the plastic exudation on the pulmonary sur- 

 face becomes by-and-by cellular in texture, 

 eventually undergoes more or less complete 

 absorption, and the immediately subjacent 

 portions of lung rise up on the removal of the 

 pressure ; the central and thick part of the 

 exudation (itself become meanwhile more or 

 less distinctly fibrous in texture) appears 

 deeper than ever in the lung, while the per- 

 fect adhesion of the edges of the sulcus in 

 which it lies, renders the illusion complete as 

 to its being seated in the actual substance of 

 the lung. 6. The adjoining pulmonary tis- 

 sue may be simply condensed, or may be 

 solidified with infiltrated plastic exudation; 

 in either case (but especially the latter) obli- 

 teration of the minute vessels and bronchi 

 takes place. The pulmonary tissue, yet be- 

 yond this, may become emphysematous. 



The more frequent occurrence of these 

 appearances at the apex than elsewhere, is the 

 obvious consequence of the great proportional 

 frequency of local pleurisy there, itself de- 

 pendent on the frequency of irritation set up 

 by tubercles in the neighbourhood. The 

 condition of the minute bronchi in the impli- 

 cated parts, is of itself a strong argument in 

 favour of the doctrine we have set forth ; 

 those tubes are contracted and obliterated 

 as they would be from pressure and disuse, 

 they are not abruptly cut across, as they 

 would be were Laennec's cicatrization-theory 

 in accordance with facts. According to M. 

 Fournet, the deep sunken, fibrous nodule may 

 become the interstitial seat of puriform or of 

 calcareous deposition. In this way he explains 

 Laennec's solitary example of partially closed 

 cavity, already referred to. We have not seen 

 this condition ourselves : the thing is no 

 doubt possible, but it must be very rare. In 

 taking leave of this question we would ob- 

 serve, that the nature of this work has pre- 

 vented us from giving it the full development 

 it really merits, but we trust enough has been 

 said to make the main fact intelligible. That 

 fact is doubtless disheartening to the thera- 

 peutist ; and we should regret any active part 

 we may have taken in establishing it, did we 

 not look forward on some other occasion to 

 proving, that anatomical cure by absorption, in 

 the manners already described, is of more 

 common occurrence than is generally sup- 

 posed. 



Many of the influences, irritative and me- 

 chanical, exercised by tubercle on surrounding 

 textures, have been spoken of in the fore- 

 going pages ; the generation of new vessels 

 attending the progress of tuberculizatiou in 

 the lung, will be touched upon in the section on 

 NEW VESSELS in another part of this article. 



3. PURULENT DEPOSIT, OR PUS. 



Pus is a fluid of whitish-yellow or greenish 

 colour, and homogeneous aspect ; of faint, pe- 

 culiar smell, when warm ; inodorous, when 

 cold ; of creamy consistence ; and of sweetish, 

 or sometimes saltish, taste. 



