Thcnnic [nflnciiccs. 43 



tissue coagulates ; the blood within the capillaries is coagulated 

 and stagnant, tlie tissue dying in consequence and being trans- 

 formed into a brownish crust (or eschar). At the border of the 

 actually involved and necrosed tissue inflammation ensues. Heal- 

 ing follows by the separation of the charred material and the 

 formation of scars, which are apt to be of a radiating, reticular 

 appearance, and which by their contraction and shrinkage may 

 cause considerable disfiguration. All these degrees of burning 

 may coexist as the heat has happened to influence in a greater or 

 less measure one or more places. 



In extensive burns of the skin (if as much as one-third of 

 the body surface is involved) the subject is likely to die. even 

 in case of burns of no more than the first or second degree. 

 Death may take place within but a few hours after the occurrence 

 of the accident with symptoms of impaired respiration, cardiac 

 weakness and fall of the body temperature. In other cases the 

 fatal end may take place after the course of a week, during which 

 there may have been apparently favorable progress, pulmonary 

 oedema and nephritis often developing in tlie meantime. Other 

 cases pursue a course of some weeks' duration before the lethal 

 end. The explanation of the dangerous features and fatal termi- 

 nation of such burns is to be sought in part in functional dis- 

 turbance of the skin in heat dissipation, fall of blood pressure, over- 

 heating and inspissation of the blood (cardiac paralysis) and in 

 part by the changes which the blood corpuscles undergo. Dif- 

 ferent investigators (Salvioli, ]\Iaragliano, Castellino, Ponfick) 

 have showm by experiment and observation upon human cases, 

 that after burns of the skin the red blood corpuscles, partly de- 

 generate (broken into small particles) and partly without any 

 apparent structural changes, are incapable of conveying oxygen, 

 and give up their hemoglobin (partly changed into methoemoglobin) 

 into the serum, whence it is excreted by the liver and kidneys ; 

 that, further, the formation of hyaline thrombi is apt to take 

 place and that these alterations of the blood may be regarded as 

 the cause of death. 



Low temperatures, which deprive the body of its proper 

 warmth, may give rise to either local or general disturb- 

 ances in warm-blooded animals. Sensitiveness to the power 

 of withstanding cold varies very much in the different animal 

 species. Fishes chilled to the freezing point may seem to be 

 lifeless, their lymph frozen into solid ice ; yet they may com- 



