40 PRACTICE OF MEDICINE. 



whole surface of the body. In the confluent^ the pustules are nume- 

 rous, and are more or less united by the close approximation of their 

 edges. 



Variola presents^bz^r stages — 1st, that of incubation^ or the latent 

 period ; being that which intervenes between the inception of the 

 poison and the first appearance of symptoms; 2d, of invasion ; 3d, 

 of eruption ; 4th, of desiccation. 



The latent period varies from six to tiuenty days. 



On the first day of the invasio7i there are more or less prolonged 

 shiverings, alternating with flushes of heat, and loss of appetite. On 

 the second clay^ there is nausea, epigastric tenderness, thirst for cold 

 acidulous drinks, a quick pulse, and hurried respiration. Children 

 are frequently seized with convulsions in this stage. The tongue is 

 loaded with a whitish or a yellowish fur, and its point is red. There 

 are pains in the head, back, loins, and limbs. These symptoms 

 continue for three oy four days. 



On the fourth day of the invasion, the eruption appears in small 

 isolated spots on the lips, face, neck, chest, abdomen, and limbs. 

 On the fifth day, the spots become more numerous, and their sum- 

 mits become vesiculous. On the sixth and seventh days, vesico-pus- 

 tular spots are observable on the skin, and sometimes on the mucous 

 membrane of the mouth, pharynx, and eyelids. Tn the intervals 

 between the pustules, the skin becomes red, and the subjacent parts 

 swollen. On the eighth day, the eruption is perfectly pustular, 

 having central indentations. The pustules being more numerous on 

 the face than on other parts, it becomes hot, painful, and tense. 

 Secondary fever now comes on, and on the ninth and tenth days the 

 central indentation disappears, and the pustules become orbicular in 

 form. On the eleventh and twelfth days, the pustules burst, and 

 desiccation commences. The crusts or scabs, now fall off, those on 

 the hands being detached a day or two later than those on other 

 situations. A thick ropy salivation is established during the more 

 advanced stages of this eruption. After the scabs have fallen off, 

 circular spots of a red-brown colour are seen on the skin, and there 

 are always small irregular cicatrices, which sometimes become the 

 seat of furfuraceous desquamation. 



In confiuent variola, all the symptoms are of a more grave type. 

 The cerebral and gastric complications are more intense, there being 

 persistent vomiting, and either delirium or convulsions. These 

 affections may cause the death of the patient before the appearance 

 of the eruption. The eruption, which is commonly simultaneous, 

 and seldom successive, occurs about the seco7id or third day, rarely 

 on the fourth, and still more rarely on the fifth. 



The pif?!tules are less prominent, and more aggregated, than in 

 simple variola, and their edges run into one another. They are 

 more numerous on the face than other parts ; and in fact, when 



