TUBERCULOUS EXUDATIONS. 141 



analyses for the examination of such substances, I have very fre- 

 quently instituted analyses of this kind with the residue (insoluble 

 in water, alcohol, and ether) of the croupous exudation of the first 

 order (a) ; but the results were so variable, that it was impossible 

 to compare them with the composition of the blood-fibrin. Accord- 

 ing to most of the analyses, the fibrin of the exudation contained 

 somewhat less nitrogen than the fibrin of the blood of the same 

 individual ; and it was only once in seven cases that the nitrogen 

 equalled the quantity found in the blood-fibrin. The quantity of 

 carbon was equally variable, for in some cases I found rather more, 

 sometimes from 1 to 2-- less, than in the blood-fibrin. 



The croupous exudation of the second order (/3 Rokitansky) 

 may be regarded as holding an intermediate place between that of 

 the first and third order when considered in a chemical point of 

 view. I have never found it to be perfectly free from pus- 

 corpuscles. 



Rokitansky distinguishes yet a third form of fibrinous exuda- 

 tion, namely, the tuberculous. Although in a purely physiological 

 or even logical point of view, we can scarcely admit the assumption 

 of such an exudation as a special form, its recognition is advantage- 

 ous in a practical point of view. We entirely set aside the idea of 

 an entirely specific process, and simply adhere to that which for 

 ages has been attached to the term tubercles. In characterising 

 this exudation, Rokitansky has here, as in other cases, not studied 

 the original fresh product of the exudation, but only the peculiar 

 form in which it most commonly comes under our notice. Persis- 

 tence in a very low stage of development has in general been 

 adduced as the most characteristic property of tuberculous exuda- 

 tions, and indeed we seldom meet with more than molecular 

 granules, minute aggregations which have been regarded as of a 

 special nature (tubercle-corpuscles), and, at most, faint indications 

 of cellular structures. The absence of plasticity in these exudations 

 has commonly been referred to the too rapid resorption of their 

 fluid parts, and either to the actual absence of blood in the smaller 

 vessels, or to other causes preventing these parts from being readily 

 permeated with moisture. Where such a permeation as this takes 

 place, we less commonly observe a formation of cells than of cytoid 

 corpuscles, which then give rise to what is termed softening of the 

 tubercles. Tubercles have been divided, as is well known, in 

 accordance with their form and mode of deposition, into miliary 

 and infiltrated, and further subdivisions have been suggested, 

 based upon their consistence and age (as for instance, gelatinously 



