SMALL-POX. 599 



SYMPTOMS AND COURSE. During the period of incubation there 

 are usually no symptoms either in mild or severe cases. After the in- 

 oculation of variola, changes occur at the point of inoculation, even on 

 the third day ; but the general health of the patient remains undis- 

 turbed, and no other symptom shows the infection till about the ninth 

 day ; as the pustule completes its development, the period of incuba- 

 tion terminates. Then there is an eruptive fever, followed by an out- 

 break of pocks on the other parts of the body, and by other signs of 

 general infection. According to the observations of Barensprung and 

 Ziemssen, the period of incubation of non-inoculated pocks lasts twelve 

 or thirteen days. 



We shall first describe the symptoms and course of the severe 

 forms, true variola, and close with a description of the milder forms, 

 varioloid. 



The first stage of variola, the stadium prodromorum sen invasionis, 

 commences with a chill, or with several rigors, which soon give place to 

 a feeling of permanent heat. The pulse is full, and frequent, the tem- 

 perature increased sometimes to 104 or 106, the face is reddened, 

 the carotids pulsate strongly ; the patients have great thirst, loss of 

 appetite, a bruised feeling in the limbs, and a sensation of pressure 

 and fulness in the epigastrium ; the tongue is coated, the taste slimy ; 

 nausea and vomiting are frequent, sometimes there is severe epistaxis. 

 Sleep is restless, and broken by dreams. Some patients become de- 

 lirious ; in children we not unfrequently see twitchings, and gnashing 

 of the teeth, or a somnolent condition, which is occasionally interrupted 

 by general convulsions. The high fever and severe constitutional dis- 

 turbance are not accompanied by such characteristic affections of the 

 mucous membranes as would enable us to decide the nature of the ex- 

 isting infectious disease before us, as we can do in the prodromal stage 

 of measles and scarlatina ; but the symptoms above mentioned are al- 

 most always accompanied by such severe pain in the sacral and lumbar 

 regions, that we may very strongly suspect the existence of small-pox, 

 when this disease is prevalent. It is not known whether the sacral 

 and lumbar pains, so characteristic of the prodromal stage of variola, 

 depend on hyperaemia of the spinal medulla, on pressure on the spinal 

 nerves, where they escape from the vertebral canal, by the distended 

 venous plexus, or on the excessive hypersemia of the kidney, concern- 

 ing which J3eer has made some important suggestions in his valuable 

 examinations into the connective tissue of the kidneys. After imper- 

 fect remissions during the second and third day, the fever and accom- 

 panying disturbances usually increase, and attain their height on the 

 evening of the third day. Generally, the intensity of the symptoms in 

 the prodromal stage is in direct proportion to the subsequent eruption, 

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