216 CONTAGIOUS DISEASES. 



surface ; and in this particular it forms a contrast both with the 

 vaccine vesicle of the cow and the variolous of man. The 

 serosity of the vesicles, first clear, becomes milky, turbid, less 

 serous, and straw coloured, and ultimately by drying hardens 

 into a crust, and is cast off with the epidermis." — (Simonds.) 



Both Professor Simonds and Mr. Ceely are of opinion that the 

 term fustuU should not be applied to the eruption, except, as 

 Mr. Simonds says, in the latter stages of extreme and protracted 

 cases, where pus is in reality formed, and is succeeded by the 

 ulcerative process. 



" The period of desquamation or dessication depends on the 

 extent of the original eruption, and also on its being distinct or 

 confluent. It is likewise governed by the amount of inflamma- 

 tory action which existed in the dermis, and is always protracted 

 when suppuration has taken place." — (Simonds.) 



The vesicles, scab, and crusts are liable to be injured in various 

 ways, but more particularly by the sheep scratching themselves, 

 and this interferes materially with the process of healing, and 

 causes considerable irregularity in the duration of the malady. 

 " In natural cases, even when mild," says Professor Simonds, 

 " and when no cause retards their completion, a month, reckon- 

 ing from the period at which the animal was first exposed to the 

 contagion, usually passes before it is restored to health. 



" The following summary of the gradations of the malady may 

 be accepted as sufficiently accurate for practical purposes : — The 

 first ten or eleven days are those of incubation; the twelfth and 

 thirteenth of invasion; the fourteenth, fifteenth, and sixteenth 

 of papulation; the seventeenth, eighteenth, and nineteenth of 

 vesication; the twentieth, twenty-first, and twenty-second of 

 suppuration; and the twenty-third to twenty-eighth of dessication 

 and separation of the crusts." — (Simonds on Variola Ooinm.) 



The same authority says that the constitutional symptoms, 

 especially those which indicate the greatest danger, " are dejec- 

 tion, the head being held low; the infected animals separate 

 from their fellows ; mostly lie down in a corner of the field ; the 

 ears are pendent; the breathing quick and short; the eyelids 

 are swollen, and tears trickle down the face; the conjunctiva 

 varies in shade from a bright scarlet to a modena red ; a mucus 

 discharge flows from the nostrils, and increases in viscosity 

 as the disease advances, often becoming sanguineous in the 



