306 THE DISEASES AND DISORDERS OF THE OX. 



developed in the general way, is about ten to sixteen days, or we 

 may say that the disease manifests itself at about the middle of 

 the twelfth day. 



The incubative stage is not attended with symptoms, or only 

 with slight symptoms. The patient may feel languid and peevish. 

 The first onset is marked by rise of temperature, chills, followed 

 by, or alternating with, heat of skin and copious perspiration, 

 severe sickness, with anorexia, thirst, and constipation (or in 

 children diarrhoea), headache, aching of the limbs, and intense 

 pain in the lumbar region of the spine, drowsiness, and some- 

 times delirium and coma. In children, diarrhoea may take the 

 place of constipation, and convulsions may occur in them. 

 Sometimes there may be maniacal excitement, vomiting, con- 

 stipation, and acute lumbar pain, with frequent convulsions. 

 The higher the temperature, the more persistent the vomiting, 

 the acuter the pain in the back, and the more pronounced the 

 cerebral symptoms, the more quickly will the disease assume 

 grave proportions. The symptoms usually attain their maximum 

 on the third day, the day on which the characteristic rash first 

 manifests itself. 



About the third day after the onset of variola, a papular erup- 

 tion first shows itself in the form of small reddish solid elevations, 

 each surrounded by a red areola, appearing both on the skin and 

 also usually on the lining membrane of the mouth, fauces, and 

 larynx. These papules gradually increase in number, and are, in a 

 few days' time, transformed into alveolated vesicles, containing a 

 transparent lymph, which soon becomes purulent. At about the 

 eleventh day the pustules attain their full development. Many 

 of them are at first depressed near the centre, but they lose the 

 peculiar appearance which is thereby caused by reason of a 

 subsequent distention of their envelopes with the purulent pus. 

 Afterwards this fluid dries, and then, instead of the pustule, a 

 dark brown crust is formed, which is finally detached, leaving a 

 scar. When these vesicles are numerous, the skin between them 

 is swollen, and when this is the case, the eruption on the lining 

 membranes of the mouth, fauces, and larynx is also more severe. 

 The fever is usually most intense before the eruption manifests 

 itself; but, though it becomes higher as the suppuration advances, 

 it soon subsides, and when the drying up of the pus begins, it 

 disappears. Of course, in very bad cases, and especially if 



