534 LIQUID PARTS OF ANIMALS. 



CHAPTER XXII. 



OF PUS. 



THE liquid called pus is secreted from the surface of an in- 

 flamed part, and usually moderates and terminates the inflam- 

 mation. It assumes different appearances according to the state 

 of the sore. When it indicates a healing sore, it is called 

 healthy or good- conditioned pus. Unfortunately this liquid has 

 not hitherto been subjected to a rigid chemical examination. 



The following are the only two analyses of pus made by any 

 modern chemist, and they are imperfect : I. That of pus from an 

 empyema by MM. Wilhelm and Martius in 1837. The patient 

 was a miller in the hospital of Erlangen, who had pleuropneu- 

 monia, with hepatization of the left lobe of the lungs. The pus 

 was extracted by an operation, and amounted to 153 German 

 pounds. 



It was destitute of smell, thick in its consistence, and had a 

 dirty greenish-gray colour. Being examined by reagents, the 

 following phenomena were observed : 



1. Litmus-paper was slightly reddened. 



2. When agitated with ether, the colour became darker, and 

 the ether assumed a yellowish colour. 



3. When mixed with absolute alcohol, many fine white flocks 

 separated, which could not be again taken up by agitation. The 

 alcoholic liquid gradually assumed a yellowish colour. 



4. When dropped into water, it sank to the bottom, and by 

 agitation it constituted a muddy liquid. 



5. Being mixed with an excess of caustic ammonia, it was 

 changed into a muddy liquid, from which white flocks were pre- 

 cipitated. The supernatant liquid was greenish-yellow. 



6. An excess of acetic acid gave a muddy liquid having a 

 peach-blossom colour. 



7. Nitric acid added in excess gave a muddy yellowish-green 

 liquid. 



8. When heated in a platinum spoon, it swelled very much. 

 When evaporated to dryness, it left a black residue, and gave 

 out a smell like that of burning flesh. 



* Ann. der Pharm. xxiv. 79. 



