44 AMYLOID INFILTRATION. 



even in persons whose organs arc most widely affected witli 

 waxy degeneration, for an albuminous substance yielding the 

 same reaction , we shall search in vain. Indeed it is only from 

 circumstantial evidence that we conclude tliat amyloid degenera- 

 tion is a genuine infiltration. 



Since amyloid matter is capable of being reddened by iodine 

 only after it has left the blood, it is right that we should show by 

 analogy that an albuminous body derived from the blood, and 

 undoubtedly forming one of its constituents, may be converted 

 into amyloid matter after it has left that fluid. I believe this 

 problem to have met with a satisfactory solution by the inquiries 

 of Friedricli and B'lermer. Any one wdio has conducted experi- 

 mental investigations on extravasated blood will at once admit, 

 that the concentrically-laminated corpuscles found by these 

 observers in ha^morrhagic deposits in the lungs, are formed by the 

 deposition of fibrin round little clusters of blood corpuscles, 

 shreds of tissue, carbonaceous particles, &c.* The fact that 

 some of these corpuscles exhibit the iodine reaction, proves 

 conclusively that here at least the fibrin of the blood must have 

 been converted into amyloid matter. We must not jump forth- 

 w^ith to the conclusion, that impregnation with fibrin is the 

 essential factor in amyloid infiltration. We need only assume 

 that an albuminous constituent of the nutrient fluid may be 

 arrested on its way through the tissues, and deposited in a solid 

 form. As the chief property of fibrinogen is its persistent ten- 

 dency to assume the solid state, this, more than any other of the 

 albnminons constituents of the blood, will have a claim on our 

 attention. Indeed, if we follow up the course of amyloid dege- 



* Those interested in the pathological histology of the lungs, will find 

 it instructive to bestow a passing glance at the forms exhibited by char- 

 coal dust under the microscope. They will see particles which may very 

 readily be mistaken for blood crystals, owing to their peculiar spiked 

 outlines and their colour, which appears a transparent reddish brown in 

 thin layers. Particles of charcoal are found in very many lungs ; for 

 their angular shape and pointed processes enable them, when introduced 

 by the respiratory act, to penetrate more easily than other foreign 

 bodies into the soft parenchyma of the lungs, where they remain fixed. 

 The presence of circular perforations renders us absolutely certain about 

 the carbonaceous nature of such pseudo-crystalline bodies ; for these are 

 the pores in the dotted cells of coniferous wood (yirchoiu's ArcMv, x. 

 Taf. iii. fig. 5). 



