268 INFECTIVE DISEASES. 



after they were attacked. The scabs then varied in size from a 

 shilling to a florin ; they were about one-eighth of an inch thick in 

 the centre, thinning off towards the edges. 



Some of the cows were also suffering from an eruption on the 

 rump and hind quarter, consisting of patches of eczematous crusts. 

 When a crust was picked off, the hair came off with it, exposing a 

 raw, moist sore, the crusts and sores looking exactly like eczematous 

 scabs and sores ; but this condition corresponds in description with 

 eczema, the result of ringworm which is very common in young 

 stock. 



In addition to his own observations, Cameron obtained infor- 

 mation from the farmers, and others familiar with cows, who 

 thought they recognised in the disease at the farm one stage of a 

 disease which they were able to describe. Cameron thus gives an 

 account of what he arid his informants together would regard as 

 a connected clinical history of the disease. 



He did not see the earlier symptoms, and hence these were 

 of necessity learnt from other persons. The account, therefore, 

 of these symptoms was to be held liable to future correction or 

 modification. 



Cameron stated that he learnt this disease was capable of 

 being communicated to milkers by inoculation with virus from the 

 vesicles on the teats, though the milkers on the Hendon farm 

 escaped. " A trusty informant received the virus into a recent 

 scratch 011 the forefinger while milking a diseased cow. General 

 weakness, malaise, and loss of appetite resulted, and after about 

 four or five days a vesicle or small blister appeared on the finger. 

 This broke, and several others formed on the back of the hand. 

 The whole hand and fingers became swollen and inflamed, the 

 inflammation extending in broad lines as far as the elbow. The 

 general disturbance lasted a fortnight." 



In the course of the inquiry, Cameron adds that it was 

 strongly asserted by several people, who examined the cows, that 

 they were suffering from cow-pox. He, however, dismissed the 

 diagnosis of cow-pox on the ground that no papule had been 

 observed or subsequent formation of pustule, areola, or pitting, and 

 because the vesicles were not umbilicated. These reasons given 

 for dismissing the diagnosis of cow-pox at Hendon were totally 

 inadequate ; a comparison having been made between the characters 

 of the eruption of vaccinia as it appears on an infant's arm, instead 

 of the eruption of the natural or so-called spontaneous disease on 

 the teats of the cow. 



