38 THE HISTORY, XATUEE, SYMPTOMS, AND 



and its developmeut varies from five to twelve days ; generally 

 about the tenth day the disease begins to manifest itself by 

 indications of a slight dulness, with diminution of appetite, 

 accompanied by feverishness. The fever is generally most 

 intense before the eruption appears, and the respirations are 

 increased, with gradual elevation of temperature, which decreases 

 when eruption sets in. In the febrile state the rythmic action 

 of the heart is altered so that the heart is unable to drive the 

 blood through the obstructed blood-vessels fast enough to carry 

 off the animal heat which is being generated, and in consequence 

 the temperature of the whole body therefore rises, and the action 

 of the various organs that are adapted to act perfectly at a fixed 

 temperature is deranged. The head is carried low, and the ears 

 drooping. The conjunctival and schniderian membranes become 

 highly injected, with a muco-purulent discharge from the nostrils. 

 The breath and cutaneous exhalations have a characteristic foetid 

 smell. The skin is hot, with tenderness over the back and loins, 

 and there is also a scantiness of urine, which has an offensive 

 odour, with a dark brown coffee colour. As this disease pro- 

 gresses and passes through the different phases which we have 

 been describing, the local symptoms begin to exhibit themselves 

 by certain characteristic alterations and appearances on the parts 

 of the body. Where the skin is finest and hairy, instead of woolly, 

 as in the flanks, thighs, and belly, there appear little pimples 

 resemblmg flea-bites, which increase in number and size, and 

 having a purple colour. These pimples assume a vesicular form, 

 and the vesicles contain a sero-purulent fluid, which is extremely 

 virulent. These have an umbilicated aspect which is peculiar 

 to the disease, and are sometimes distinct and sometimes con- 

 fluent. If they are confluent, and the fever remain unabated, 

 then we may almost be certain of an unfavourable termination. 

 In due course the contents of the vesicles have become trans- 

 formed into pus, which constitutes the pustular stage, when they 

 are considered to have become mature. From three to five days 

 from this time, if ulceration does not follow, the pustules dry up, 

 lea^dng brown scabs, perfectly formed, which then drop off, if not 

 injured by rubbing, and leave a little red depression in the skin. 

 There are two forms of this disease, regular and irregular. 

 The symptoms enumerated in the preceding description may be 

 designated under the regular form, but it is found that in a flock 

 the methodic course is rarelv followed or marked, nor is it to be 

 wondered at when we consider that the constitutions, conditions 

 of the blood, and the general health of the animals differ, while 

 in some there is a peculiar idiosyncrasy to the contagion of 

 variola. In the irregular or malignant form the eruption appears 

 slowly and intermittent, and has a greyish red tint. The eyes 

 are dull and have a muco-purulent discharge. The head, nostrils, 



