PURIFORM SOFTENING OF THROMBI. 233 



of the blood, to the formation of the clot (thrombus), it 

 seems most convenient to comprehend the whole of this 

 process under the term Thrombosis. I have proposed to 

 substitute this term for the different names, phlebitis, ar- 

 teritis, etc., inasmuch as the affection essentially consists 

 in a real coagulation of the blood at a certain fixed spot. 

 Upon investigating the .history of these thrombi, we 

 find that the puriform mass which is met with in their 

 interior does not originate in the wall, but is produced 

 by a direct transformation of the central layers of the 

 clots themselves, a transformation indeed which is of a 

 chemical nature, and during which, with a result similar 

 to that which can be artificially obtained by the slow 

 digestion of coagulated fibrine, the fibrine breaks up into 

 a finely granular substance and the whole mass becomes 

 converted into debris. This is a kind of softening and 

 retrograde metamorphosis of the organic substance, in 

 the course of which from the \ ery commencement a num- 

 ber of extremely minute particles 

 FlQ " 70> become visible ; the large threads 



of fibrine crumble into pieces, these 

 again into smaller ones, and so on 

 until after a certain time has 

 elapsed the chief part of the mass 

 is found to be composed of small, 



fine ' P ale g ranules ( Fi S- >70 ' A }- 

 In cases in which the fibrine is 



comparatively very pure, we frequently see scarcely 

 anything else than these granules. 



Fig. 70. Puriform mass of debris from softened thrombi. A. The granules seen 

 in disintegrating fibrine, varying in size, and pale. B. The colourless blood-cor- 

 puscles set free by the softening, some of them in process of retrograde metamor- 

 phosis; a, with multiple nuclei, 6, with simple, angular nuclei and a few fat-gra- 

 nules, c, non-nucleated (pyoid) corpuscles, in a state of fatty metamorphosis. O. 

 Red blood-corpuscles undergoing decolorization and disorganization. 350 diame- 

 ters. 



