Volume 4

The cyclopaedia of anatomy and physiology / edited by Robert B. Todd.

Date:
1836-1859
Catalogue details

Licence: Public Domain Mark

Credit: The cyclopaedia of anatomy and physiology / edited by Robert B. Todd. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

    126/702 (page 110)
    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 jyrogress of contraction during life would frequently occur, whereas it has certainly never yet occurred to ourselves, nor (so far as we are aware) as ^natter 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. (I.) 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-jml- monarij 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. ]. Pleurisy occurs, local or general, with or without liquid eff'usion. 2. The resulting plastic exudation penetrates or not into sulci on the pulmonary surface formed by creas- ing ; these sulci are deeper if liquid efllision 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 tuberculization 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.