VARIOLA. 



39 



diminish in size, and shrivel at their circumference ; and on the fifth, 

 a small crust, adherent to the skin, is formed at their centre. On 

 the sixth day, small yellowish and brownish crusts occupy the place 

 of the vesicles ; on the seventh, or eighth, the crusts fall off, leaving 

 on the skin red spots, without depression, which remain for some 

 days. 



This is the usual type of this disease ; but sometimes it assumes a 

 pustulous form, in which case the accompanying symptoms are 

 more severe, and the disease assumes, to some extent, the charac- 

 ters of small-pox. This form has been divided into three kinds, 

 which, differing in the external characters of the pustules, and in the 

 progress of the eruption, have received the names of conoid, globu- 

 lous, and umbilicated pustulous varicella. Pustulous varicella has 

 been, and may readily be, confounded with variola, some believing 

 that it is an imperfect form of that disease. 



The external characters which distinguish varicella from variola 

 are — 



1. The shorter duration of the vesicles, or pustules in varicella. 



2. The small red spots of varicella, on the first day of their ap- 

 pearance, feel to the finger like a flat seed ; on the contrary, in the 

 same stage, the elevations of small-pox give the sensation of touching 

 a round seed, and the sanguineous injection is much greater. 



3. In varicella, the serosity, or pus, fills the vesicles, or pustules, 

 on the first or second day of the eruption ; in variola, the formation 

 of the serosity is slower, and only takes place at the summit of the 

 pustules. 



4. Lastly, in varicella, the eruption is not so simultaneous as in 

 small-pox ; some vesicles and pustules appearing in the former, 

 at the same time that the desiccation of others has commenced. 



Treatme7it. — When varicella is distinct and apyretic, the treat- 

 ment is very simple ; the patient should remain in bed in a tempe- 

 rate atmosphere, have a mild purge, ought to be placed on low diet, 

 and abstain from animal food for a few days, and should partake 

 freely of diluent drinks. Tepid baths may be employed during 

 convalescence. 



VARIOLA. 



This is a contagious eruptive fever, affecting at the same time the 

 gastro-pulmonary mucous membrane and the skin. It shows itself 

 externally from the third to the fourth day of the febrile invasion. 

 At first it is papular, it then becomes vesicular, and next p)ustules 

 are formed, which at first are p)oiated, and then become umbilicated. 

 This affection terminates, after from twelve to fifteen days' duration, 

 in desiccation and scabbing, small irregular cicatrices remaining. 



Variola is commonly divided into the distinct and confluent forms. 

 In the distinct, the pustules are few and thinly scattered over the 



