224 MANNER IN WHICH 



come much enhanced. In certain fevers the disease 

 germs may increase in the blood to such an extent 

 during the period of incubation, that the rigors and 

 vomiting which mark the commencement of the 

 actual fever may be followed by death in a very few 

 hours. In some of these terribly fatal cases, it is 

 possible that the capillaries of the mervous centres 

 may be the seat of obstructed circulation ; in others 

 the fatal result may be occasioned by rapid chemical 

 changes set up in the blood, and an indirect effect 

 upon the nerve centres produced through the nerve 

 fibres distributed to the capillaries ; but in some 

 instances the state of the capillary circulation in all 

 parts of the body justifies the inference that the fatal 

 result is actually due to the cessation of the circula- 

 tion in the obstructed capillary vessels distributed 

 everywhere. 



In fatal contagious fevers, death more commonly 

 occurs some days after the commencement of the 

 attack, and may be ascribed to the obstruction to the 

 circulation caused by gradual plugging of capillaries 

 in every part of the body, consequent upon the multi- 

 plication of the contagious bioplasm, and the changes 

 resulting from this phenomenon. The process has been 

 already described in pp. 121 to 126, 179 et seq, and the 

 indirect consequences have been referred to. In 

 many instances I have carefully studied the several 

 changes in the capillaries of various tissues of the 

 body, and in a most instructive case of glanders, I 



