46 Causes of Disease. 



occurrence of paroxysms of colic (dysperistalsis) in sweating 

 horses after cliilling of the surface cannot be denied. Rabbits and 

 guinea pigs dipped into ice-cold water have been known to 

 quickly sicken and die from pulmonary and renal inflammatory 

 affections. As a further illustration it is well known that the 

 peritoneum is very susceptible to the effects of lowered tempera- 

 ture, and that in case of extrusion of the viscera or in operations 

 involving the exposure of the peritoneal cavity there often arise, 

 even at a temperature of 21° C, entirely from the chilling (under 

 conditions of asepsis and in the absence of other causes), a gen- 

 eral depression of temperature, attacks of colic, peritonitis and 

 perhaps a fatal termination. 



Hofer has observed that chilling may affect even fishes, provided they 

 be suddenly changed from a warm water to a cold ; and that such chilling 

 causes changes in the skin (desquamation and necrosis of the epithelium). 



Attempts to frame a theory explanatory of the real nature 

 of chilling have as yet been unproductive of any definite informa- 

 tion on the subject. If it be assumed that the blood in the 

 cutaneous vessels is chilled, it remains imexplained why practi- 

 cally only isolated parts of the body are affected, although the 

 chilled blood flows on to other organs. Excretion of blood pig- 

 ment in the urine (hsemoglobinuria) after exposure to cold 

 might well be explained upon the idea of chill effects upon the 

 blood causing destruction of the corpuscles, yet in such cases of 

 hsemoglobinuria there is usually a previously developed myositis 

 and the red color of the urine is looked upon as a result of the 

 liberation of muscle pigment and not as depending solely on 

 blood destruction. The chilling of the skin causes extensive vas- 

 cular constriction and the blood is forced from the surface and 

 accumulates in the internal or more deeply lying parts of the 

 body. Why in these cases the blood is not evenly distributed 

 in the body, but collects in special localities, is an open question. 

 Sudden exposure of a cutaneous or mucous surface to cold un- 

 doubtedly causes an appreciable vascular tonic contraction, which 

 may be ascribed to stimulation of the vaso-motor nerves. This 

 vascular spasm is not limited to the area directly affected by the 

 cold, but extends consensnally or reflex! y to adjacent or symmetri- 

 cal, or distant vascular areas (Samuel). If, for example, one dip 

 a hand into very cold water the other hand also becomes paler 

 (Samuel), and probably everybody has had the experience that oc- 



