TATTY DEGENEHATION. 27 



could only result from antecedent tuberculous disease ; it used 

 to be viewed as a direct excretion of tlie 7nateries morhi from the 

 blooclj and was hence denominated '^ crude " or '' raw " tubercle. 

 The term " tuberculisation" was nearly synonymous with what 

 we now call caseation. Reinhard was the first to overthrow the 

 belief in the specific character of this deposit ; he erred, how- 

 ever, in declaring it to consist invariably of inspissated pus. It 

 was resers^ed for Firclioio to place the matter in its right light, 

 by describing " cheesy necrosis" as a tolerably widespread mode 

 of degeneration of tissues rich in cells. 



§ 34. The reader will recollect that in describing fatty meta- 

 morphosis, I stated that the presence of a certain quantity of 

 water was essential for the actual disintegration of the cells, in 

 oiTler to dissolve the albuminoid material which held the oil 

 globules of the granule cells together. Should this fluid be 

 wanting, as happens when large masses of newly formed cells 

 are traversed by few or no pervious vessels, the process of fatty 

 metamorphosis is somewhat modified; the two modes standing 

 in much the same relation to one another as that in which dry 

 gangrene stands tovv^ards the moist variety. The cells dry up, 

 they shrink into comparatively small, shapeless, mostly angular 

 bodies, in which, besides the oil globides, a considerable number 

 of granules — the so-called protein molecules — may be distin- 

 guished. The less the amount of water present, the more does 

 the whole wither into a dense, yellowish-white mass, in -which 

 the remnants of cells can be demonstrated, even after the lapse 

 of years. True, we are unable to restore the withered cells to 

 their old shape by the addition of Avater ; this usually breaks up 

 the molecular aggregates, forming a sort of emulsion. Similar 

 changes occur if the cheesy matter should subsequently absorb 

 moisture and soften in the organism itself. 



This constitutes, as we shall see hereafter, a most destructive 

 episode in the history of tuberculosis ; the softening occm'ring 

 by preference in such portions of the cheesy deposit as come to 

 the surface on the walls of the internal cavities of the body, 

 whether in the respiratory or digestive tract, and are accordingly 

 exposed to other sources of moisture besides the nutrient juices 

 in which they are bathed. In parts w^hich do not communicate 

 with free surfaces, as in the lymphatic and mesenteric glands, 

 in the bones, the brain, and spinal cord, softening of the cheesy 



