ADHESION. 



53 



more readily as the tissue may be more cellular 

 and vascular. That these organs are very vas- 

 cular is evident from the rapidity with which 

 they bleed upon the slightest contact ; that they 

 contain nerves is shewn by the pain which 

 is produced in them by the slighest touch : 

 does not their prompt destruction by slight 

 causes seem to indicate the existence of' absor- 

 bents ? 



No one has made more interesting researches 

 into the nature of these bodies than Sir Everard 

 Home.* He carefully observed the changes 

 which occurred in an ulcer of the leg. By using 

 a lens which enlarged objects eight times, he 

 saw that granulations were formed in the fol- 

 lowing manner : first, is seen a mass of capil- 

 lary vessels differently arranged ; secondly, 

 small sinuosities containing pus. The ulcer ob- 

 served during ten minutes, offered, in the first 

 place, an extremely thin and transparent pel- 

 licle, under which were disengaged globules of 

 gas, then canals having a horizontal direction, 

 and containing blood. The tunics of these 

 vessels were so delicate that they were ruptured 

 by the simple motion of the leg. These canals 

 anastomose with each other, taking different 

 directions ; those which are developed the first 

 were the next day changed into true vessels. 

 Soon these new vessels have enough of solidity 

 to admit of our passing a needle under them 

 and raising without rupturing them. The forma- 

 tion of all these parts is due, according to 

 Home, to the coagulation of pus, and the de- 

 velopment of carbonic acid gas ; " for if the 

 puriform matter be wiped off, these phenomena 

 are not produced." When, on the contrary, he 

 employed substances, calculated to coagulate 

 the pus, the formation of those vessels was 

 accelerated. He concludes from his experiments 

 that bloodvessels are developed, almost as it 

 were under the eye of the observer ; that they 

 are not a prolongation of pre-existing vessels ; 

 that they are formed independently of the action 

 of the subjacent solid parts. So far, therefore, 

 although the processes may differ, yet the 

 general points of union between the two modes 

 is singularly similar. 



While suppuration is proceeding, another 

 operation is in progress under the layer of gra- 

 nulations. A stratum of cellular tissue, at first 

 simple and not very resistent, afterwards fibro- 

 cellular, and lastly fibrous, is organised insensi- 

 bly to serve as the base of the succeeding me- 

 dium of union. 



When granular surfaces are brought into con- 

 tact, and the tendency to secrete pus has ceased, 

 they enter into adhesion. This tendency is 

 marked by a diminution of activity in the gra- 

 nulations; the membrane ceases to secrete pus, 

 and the granulations become firmer and con- 

 tracted : before union can be effected, the sup- 

 purating surface must, therefore, change its 

 nature must be destroyed. A state like that in 

 simple union by the first intention is produced ; 

 the secretion becomes plastic, and somewhat 

 analogous to that which accompanies that mode 

 of union. 



* Home on Ulcers. 



When these new tissues or media of union 

 are developed between surfaces naturally free, 

 the structure of the two portions of the organ 

 between which they are seated becomes changed. 

 In serous or mucous membranes, as well as in 

 those surfaces which are immediate modifica- 

 tions of these two systems, this may be ob- 

 served. When, for example, the pleura costalis 

 becomes adherent to the pleura pulmonalis, the 

 point of union is no longer a serous membrane ; 

 the free surface having disappeared, an un- 

 interrupted continuity is established between 

 the subserous cellular tissue of the pleura cos- 

 talis, and the interlobular cellular tissue of the 

 lung. This conversion is frequent in the peri- 

 toneum ; in the tunica vaginalis a similar effect 

 is produced by the common operation for hy- 

 drocele ; in synovial membranes a similar effect 

 occurs in what is termed false ankylosis. 



Having described the general laws by which 

 the phenomena of adhesion are governed, I 

 shall now point out, generally, the modifica- 

 tions which are impressed upon it in different 

 tissues. 



It is upon serous membranes that we may 

 with most advantage study the process of ad- 

 hesion, not only because it is more rapidly 

 developed there, but because it much more 

 frequently occurs there than in other tissues. 

 If we examine the surfaces of two such mem- 

 branes which have been recently united, com- 

 mencing at a certain distance from the point of 

 adhesion, we see the layer of coagulable matter 

 effused between the two surfaces become thinner 

 as we approach the point of contact. If the 

 adhesion be sufficiently recent to admit of our 

 separating the surfaces, we see the intermediate 

 layer tearing, but remaining adherent to the 

 inflamed surfaces. If the inflammation be 

 more advanced, and the pseudo-membrane be 

 more dense and organised, we find that the 

 very thin layer of new deposition by which the 

 union has place is more resistent than the 

 thicker layer of organisable matter by which it 

 is surrounded ; and at a later period we may 

 discover vascular filaments attaching the ad- 

 herent portion of the new tissue to that upon 

 which it has been developed. These filaments 

 are as much more evident as the adhesion is 

 more immediate : of this we may very easily 

 assure ourselves by cutting transversely two 

 portions of digestive tube which have become 

 to a certain extent adherent by their external 

 tunic. The adhesion may be already very 

 solid at the points where contact is so imme- 

 diate that we can scarcely distinguish the in- 

 terposed matter. Very delicate red capillaries 

 creep through this matter, whilst perhaps at the 

 distance of some lines, and even at the centre of 

 an already organised point, the contact having 

 been less immediate, a plastic layer of one, 

 two, or more lines in thickness, may be seen 

 uniting the surfaces, but not presenting either 

 the solidity or the organisation of the exces- 

 sively thin layer which adjoins it. 



When these adhesions have existed for a cer- 

 tain time, the serous structure completely dis- 

 appears. This destruction of serous membranes 

 at the adherent point is very evident around 



