PRODUCTS, ADVENTITIOUS. 



Ill 



Pus consists of a liquid part (liquor puris) 

 holding in solution organic principles and in- 

 organic salts ; and of a solid part (corpuscles') 

 held in suspension in the liquor puris. These 

 constituents separate spontaneously, after re- 

 moval from the body, with a degree of slow- 

 ness increasing as the purity of the pus ; when 

 the liquor puris is in excess, the corpuscles 

 sink rapidly. The corpuscles are not sepa- 

 rable from the liquor puris by filtration. Pus 

 does not naturally contain gas of any kind 

 (J. Davy). Its specific gravity ranges between 

 1042 and 1021, the weight most commonly- 

 observed being about 1030. 



Four kinds of organic corpuscles are found 

 in pus : (1.) Proper pus-corpuscles ; (2.) Py- 

 oid corpuscles; (3.) Granules ; (4.) Compound 

 granule-corpuscles. 



(1.) The proper pus-corpuscle is a body of 

 tolerably spherical outline, unless when acci- 

 dentally flattened or otherwise altered in shape 

 by the pressure of adjoining corpuscles ; its 

 edge, slightly dentated, as we have commonly 

 seen it, may be perfectly even ; its surface 

 finely granular-looking. The corpuscle is 

 (commonly, but not always,) moderately trans- 

 parent, subjacent bodies being visible through 

 it, as is particularly obvious when a weak 

 iodine-solution has been added to the fluid. 

 The diameter of the corpuscle varies from the 

 -i^vo to the -JOQ- of an inch, averaging about 

 the Tj-oV-o- Its substance is somewhat elastic. 

 It never, as far as we have seen, presents a 

 narrow edge to the eye, in the manner of the 

 red corpuscle of the blood. 



The contents of the corpuscle are semi- 

 fluid and solid. The semi-fluid substance 

 seems of slightly gluey consistence. The solid 

 contents are the nucleus or nuclei. It was 

 long taught that if the pus examined be recent, 

 and chemically unchanged, the nucleus is not 

 perceptible even with strong magnifying powers. 

 This is now known to be erroneous ; we have, 

 with a glass magnifying only 400 diameters, 

 detected a nucleus in laudable pus of neutral 

 reaction, immediately after removal from the 

 body.* But, under the influence of dilute acetic 

 acid, the nucleus is more fully brought into 

 view, and is seen close to the cell-wall, in the 

 form of a bipartite, tripartite, or quadripartite 

 body (more rarely a single one), all the divisions 

 of which lie nearly on the same plane side by 

 side. Each division of the nucleus is smooth, 

 circular, or slightly oval, and biconcave. The 

 central depression, which exists as a conse- 

 quence of its biconcave form, either appears 

 opaque, while the surrounding part is clear 

 and transparent, or the former is transparent 

 and the latter opaque, differences depending 

 on variation of the focus of the microscope. 

 The surface of the nucleus is very finely 

 granular ; its diameter varies from the ^- 3 Vo to 

 the r of an incn - 



* The facility of its discovery depends upon the 

 transparence and thinness of the cell-wall ; and the 

 amount of these, upon the youth of the corpuscle. 

 In our work on Cancer (fig. 6) are figured nuclei 

 visible without the aid of acetic acid. 



(2.) Under the name of pyoid, M. Lebert* 

 distinguishes a corpuscle smaller than that just 

 described ; spherical in shape, tolerably trans- 

 parent, rather of solid than liquid consist- 

 ence ; containing from four to ten granules or 

 more in their interior, and wholly unprovided 

 with nucleus, acetic acid simply rendering the 

 corpuscle more transparent. These bodies, 

 resembling most closely the cells of tubercle 

 (p. 105), are larger and more spherical than 

 these : so great is the similarity, that M. Lebert 

 was at first led to consider the pyoid cor- 

 puscle peculiar to tuberculous pus ; but, sub- 

 sequently finding it (as we have also done 

 ourselves) under circumstances excluding the 

 idea of tubercle, has relinquished this notion. 



(3.) The elementary granule seen in pus is 

 of spherical shape ; it is never cupulated, so 

 far as we have seen, and is less than half the 

 size of the nucleus of the pus-corpuscle, ave- 

 raging the Y^^-O^ of an inch in diameter. 

 These granules are obviously not, as was once 

 maintained, detached nuclei floating in the 

 liquor puris. They are either single and soli- 

 tary, or (less frequently) collected in irregular 

 groups. Their composition varies, as they are 

 sometimes soluble in aether, and sometimes 

 exhibit the reactions of a protein-compound ; 

 this chemical difference is not always con- 

 nected with any physical peculiarity, which the 

 eye at least can detect. 



(4.) The compound granule-corpuscle (com- 

 pound inflammation-globule; Gluge) does not 

 occur in large numbers in pus ; many drops 

 may be examined without a single one pre- 

 senting itself. This corpuscle is of spherical, 

 and slightly irregular, form, ranging from 

 to TTTTO f an i ncn in diameter (fig. 



Fig. 92. 



Compound granule-corpuscles (magnified 400 diams.). 



a, in the natural state, diam. = T 5 33 to y^g of an 

 inch ; b, corpuscle ahout to undergo rupture, the 

 involucrum being more transparent, and the gra- 

 nules larger, darker, and more prominent ; c, a cor- 

 puscle treated with dilute acetic acid, the involucrum 

 being rendered transparent, and several nuclei ap- 

 pearing in its interior. 



92) ; and composed essentially of granules 

 and an involucrum. The involucrum is not 

 dissolved by water, and s'mply rendered trans- 

 parent by acetic acid ; the granules vary from 

 ten, to twenty or thirty, or even many more 

 in number. Occasionally the action of acetic 

 acid discloses a single, double, or multiple 

 nucleus lying close to the involucrum. The 

 granules are likewise kept in situ by a fluid of 

 thickish consistence, in which, if few in num- 

 ber, they may be seen to move. The course 

 of formation of these corpuscles seems to be, 

 agglomeration of granules from exudation 

 matter, investment with a membranous wall, 

 production of a nucleus. 



* Physiol. Patholog. t. i. p. 46. 1845. 



