112 



PRODUCTS, ADVENTITIOUS. 



Fat occurs invariably in more or less quan- 

 tity in pus, and exhibits itself under the micro- 

 scope, under the forms of molecular granules, 

 as above referred to ; oil globules ; crystals of 

 cholesterin. 



Saline crystals occasionally occur in pus, 

 especially in certain unhealthy varieties of the 

 fluid. When they exist, some peculiar cir- 

 cumstances have probably caused unusually 

 rapid, or otherwise modified, evaporation of 

 the liquor puris. 



Infusoria (monads and vibrions, especially 

 the vibrio lineola) occur in pus : we are un- 

 able to affirm whether their presence is always 

 an evidence of decomposition in the pus itself. 

 The attempt, made by Gruithuisen, to dis- 

 tinguish various fluids by the characters of the 

 infusoria developed within them, has not led 

 to any satisfactory results. 



Pus, when recent and healthy, has a slightly 

 alkaline reaction ; we have known it neutral, 

 however, in cases where there was no reason 

 to believe any chemical change had occurred. 

 It readily becomes acid from the development 

 of an acid the lactic it is supposed : the 

 change from one to the other reaction, evi- 

 dently depends, in some cases, on a primary 

 change in the constitution of the pus at the 

 moment of generation ; for we have found pus 

 from the same wound, sometimes alkaline, 

 sometimes acid, though taking all precautions 

 to ensure its examination at the moment of 

 production. 



The published analyses of pus are extremely 

 numerous. Among the most recent and care- 

 fully conducted are several by Dr. Wright *, 

 of which the following may be selected as 

 specimens ; it is clear that the chemical con- 

 stitution of the fluid must vary somewhat 

 with the locality from which it has been de- 

 rired, inasmuch as pus can very rarely be 

 obtained free from minute quantities of the 

 textures or secretions in connection with 

 which its production has occurred. 



Some of the discrepancies in the results 

 given by various experimentalists, doubtless 

 depend in no small degree on the differences 

 in the manner of conducting their analyses. 

 Making allowance for these sources of error, 

 it may be inferred that liquor puris consists 



* Medical Times, January, 1845. 



of water varying in proportion from 76 (Von 

 Bibra), and 82 (Dumas), to 90 (Lassaigne, 

 Pearson, and Von Bibra*) per 100, of dis- 

 solved albumen, of fibrin, fat, and extractive 

 matters. A peculiar principle (precipitable by 

 acetic acid and by alum) has been assigned to 

 pus, under the name of pi/in, by Guterbock : 

 that such a special substance exists independ- 

 ently of the means employed to procure it, has 

 been questioned or denied by Valentin, Dr. 

 John Davy f, and others. At the present 

 hour the real presence in pus of the principle, 

 described under this name, is admitted by 

 chemists ; it is said (probably pro tempore) to 

 be tritoxide of protein. Glutin is enumerated 

 by Martins J among the constituents of the 

 pus of empyema ; its existence must be an 

 exceptional occurrence. Phosphoric, hydro- 

 chloric, and lactic acids in union with lime, 

 potassa, soda, magnesia, and ammonia, form 

 the ordinary saline elements of the fluid. Oxide 

 of iron, though put forward as a constant in- 

 gredient by Cruickshank, Koch, Krauss, Gobel 

 (in the horse), Pearson, and Gliterbock, is in 

 all probability only present in instances of ac- 

 cidental admixture of blood. 



The micro-chemical properties of the pus- 

 corpuscle are important. Pure water exercises 

 no obvious influence on it for days, even, ex- 

 cept that of rendering the nucleus more visible, 

 and slightly increasing its size by passing 

 through the cell-wall by imbibition. Saturated 

 sugar- water, blood, mucus, and saliva, unless 

 (as observed by Henle) the latter be acid, 

 produce scarcely any alteration in the cor- 

 puscle. Urine gives it an extremely ragged 

 outline in the course of a few days (earlier if 

 it be alkaline), and eventually breaks it up 

 completely. Alcohol slightly corrugates, with- 

 out dissolving it. Under the action of acetic 

 acid the corpuscle loses its granular appear- 

 ance, commonly undergoes a change of bulk ; 

 and the distinct outline of the involucrum 

 fades away, while the nucleus, simple or com- 

 pound, becomes clear and distinct. W T hat is 

 the nature of these changes ? The removal of 

 the granular aspect of the corpuscle is not 

 readily explained. We were at one time dis- 

 posed to regard it as produced by the simple 

 unfolding of the involncrum, caused in turn 

 by imbibition of the fluid re-agent, believ- 

 ing that the granular appearance arose simply 

 from a corrugated state of the surface of the 

 involucrum. But the uniformity of the gra- 

 nular appearance, its constancy of occurrence, 

 its extreme delicacy, and the fact that it is 

 not removed altogether, no matter how dis- 

 tinctly the corpuscle be swollen by imbibition, 

 appear to throw doubt upon this view, and 

 render it more probable, if not actually cer- 

 tain, that it depends on the presence of mo- 

 lecular matter within the involucrum; the 

 change of bulk is sometimes one of increase, 

 sometimes one of decrease, a difference 

 which has appeared to us traceable to the 



* Untersuch. iiber einige verschiedene Eiterarten. 

 Berlin, 1842. 



t Physiological and Pathological Researches, 

 j Annalen der Pharrnacie. 



