TRANSACTIONS OF THE SECTIONS. 113 



islands arising from tuberculous diseases amounts to one-fourth of the 

 entire population, proceeded to describe the appearances of tubercles in 

 the lungs, and entered into a consideration of the prevailing doctrine 

 respecting their nature, viz., that they are inorganizable bodies consist- 

 ing of lymph of a vitiated character, and analogous in every respect to 

 the depositions which take place in scrofulous tumours near the surface 

 of the body, and that therefore those most influential authorities, Clarice, 

 Carswell, and Todd, insist upon the actual identity of the two diseases. 

 From this opinion Mr. Carmichael altogether dissents, although willing 

 to admit that the scrofulous constitution is above all others most dis- 

 posed to tuberculous consumption, and argues from the following facts 

 that tubercles are parasitic entozooa, in the possession of independent 

 life, and no further connected with the animal in which they are lodged 

 than that they draw from it the materials of their growth, which they 

 imbibe and assimilate by their own innate powers. 



1 . Scrofulous tumours are preceded and attended by more or less 

 inflammation, which tubercles are not, as is admitted even by those who 

 contend for the identity of the two diseases. 



2. Tubercles either present the appearance of grey semi- transparent 

 vesicles, or of round compact granular-like bodies of a medullary ap- 

 pearance, totally unlike the depositions that are formed in scrofulous 

 tumours ; but when they are clustered together in great numbers they 

 may be compressed into each other, so as to give the appearance 

 of an extended inorganized substance, and in such a state may be 

 moulded into the form of the parts in which they are found ; a cir- 

 cumstance that has afforded an argument not deemed conclusive by 

 Mr. Carmichael in favour of the opinion that the tuberculous substance 

 is nothing more than vitiated lymph or strumous matter. 



3. Tubercles cannot be injected (as was evinced by the prepara- 

 tions laid before the Meeting), while no one wiU contend that scro- 

 fulous tumours are not easily injected ; therefore, as the former have 

 no communication by vessels with the surrounding parts, and as they 

 increase sometimes even to an enormous extent, it is inferred that their 

 production and growth depend upon their internal powers, by which they 

 imbibe nourishment from the surrounding parts. 



4. The tuberculous substance, as long as it maintains life, will not 

 give the stimulus of an extraneous body, as is exemplified by the facts 

 adduced respecting the FUia medinensis, or Guinea worm ; but when it 

 dies it causes inflammation and its consequences in the surrounding 

 parts : the softening process then takes place in the tuberculous sub- 

 stance, which (when these bodies are produced in the lungs) is either 

 expectorated by its making its way into the bronchial tubes in the 

 form of a peculiar well known tenacious matter which has neither the 

 properties of pus nor mucus, or it is absorbed, leaving scarcely more 

 behind than the earthy particles it contained, which appear in the con- 

 sistence of chalk and water, or soft putty, lodged in a shrivelled carti- 

 laginous cyst. 



5. Pathologists and chemists agree in the fact that a large proportion 

 of phosphate and carbonate of lime is found in tubercles, and it is 



