MUCUS. 85 



quence of the fewer air-bubbles that are inclosed, (on account 

 of slighter tenacity of the fluid medium of communication, and 

 the comparative facility with which they escape,) and partly in 

 consequence of the greater amount of albumen in the fluid, and 

 its higher specific gravity. If the secretion is composed of 

 nearly equal parts of mucus and pus, it sinks rapidly to the 

 bottom, and forms small definite tough clots : the masses may 

 easily be broken up by means of a glass rod, and can often be 

 separated by mere shaking : they have not so uniform an ap- 

 pearance as the healthy or morbid clots of mucus which float 

 on water, but to the naked eye they appear finely granulated 

 or gritty, since, in consequence ' of the deficiency of the con- 

 necting medium the mucin, the cells of the secretion are not 

 so closely associated. 



When there is only a small amount of pus in the globular 

 sputa during phthisis, it separates from the mucus on being 

 placed in water ; the pus at once sinks, and while the mucus is 

 still floating on the surface we may observe long dependent 

 viscid fibres, at the extremities of which white or yellowish gra- 

 nular particles of pus may be noticed. 



Phthisical sputa deposit a whitish granular sediment at the 

 bottom of the vessel, while masses of mucus are still floating on 

 the surface of the water. A microscopic examination of the 

 sediment shows that it consists of cells, which closely resemble 

 mucus-cells, especially when they have been in the water for 

 any time : since, however, the cells of purulent sputa come in 

 contact with the water more readily in consequence of the 

 smaller quantity of the connecting medium, mucin, they swell 

 and become larger than the mucus-corpuscles, after they have 

 been for only a short time in water : the capsules become 

 transparent and vesicular, the granular appearance vanishes, and 

 one, two, three, or even more nuclei with internal nucleoli, be- 

 come visible : the capsules of many of the cells burst, and the 

 nuclei swim about in a state of freedom, in the same manner as 

 we observe in mucus that has been long under water. A mi- 

 croscopic representation of these pus-corpuscles is given in 

 fig. 17. The water in which purulent mucus has been placed 

 differs materially from that in which normal or diseased mucus 

 has been swimming. It is either nearly clear and colourless, 

 or else of a pale yellow tint, is viscid, and is slightly clouded 



