1 X l-'L A M _M AT 1 ( ) X . 1 5 5 



exudate. Intense irritants are tisuallv the causative aoents of 

 hemorrhagic inflammation. Croupous pneumonia is cliaracter- 

 ized by a hemorrhagic exudate. 



A so-called purulent exudate has l)een descril^ed but pus is 

 not purely exudative for some of its constituents are not de- 

 rived from the Ijlood. Pus is composed of altered leucocytes, 

 tissue shreds, and usually bacteria, suspended in a fluid Ii(|uor- 

 puris. Liciuor puris is blood jjlasma and dissolved tissue. Pus 

 contains no fi1)rin, the proteid constituents l)eing converted into 

 soluble compounds by cellular enzymes and bacterial ferments. 



3. The following are pr(.il)a1dy the determining factors of the 

 quality and quantity of inflammatory exudate. 



n. Cause of inflammation: — Generally speaking a mild irritant 

 or injury produces a serous inflammation, and an intense ir- 

 ritant produces fibrinous inflammation. Mechanical injuries, 

 when there are no surface abrasions, produce an inflammation 

 of a mild degree and the exudate is limited m (plantit^■ and is 

 usually of a serous nature. Such injurie:;, however, usually 

 produce abrasions which fa\'or the invasion of micro organisms. 

 Thermal disturbances of mild degree, produce a serous ex- 

 udate, if more severe the exudate is extensive and of a fibrin- 

 oirs or hemorrhagic character. The rise of a thermo-cautcr\- is 

 an excellent example of thermal profluction oi inflammation and 

 the se\'eritv of its use demonstrates the intensitv of inflanuua- 

 tion and the variations of the exudate. An irritating chemical 

 substance injected into a tissue produces inflammation char- 

 acterized b)' excessi\'e exudaticin es|)ecially of a serous fluid. 

 T.ie more irritating the chemical, the greater the cpiantitv of 

 exudate and the greater the percentage of proteids. External 

 application of chemical irritants ].iroduces inflannuation char- 

 acterized by a serous or hv a fibrinous exudate. This latter 

 m.av be observed in the ap])lication of blistering agents. In- 

 fective inflammation is usually accompanied by a marked exu- 

 date from the beginning of the infection. The quantity and 

 quality of the exudate varies with the virulency of the organ- 

 ism. There are some exceptions hov.-ever, e. g., tetanus infec- 

 tion causes a verv limited exudate regardless of the virulency 

 of the tetanus bacillus. In some infections, as malignant 

 oedema, the exudate is largely fluid. In suppuration the ex- 

 udate is almost entirely leucocytic. 



/). Condition of the animal etTected. The exudate is usually 

 limited in animals having normal vessels, heart action, and 

 blood. In those animals in which the vessels are diseased and 

 especially if the endothelium has been injured there is a t 



en- 



