190 CONTAGIOUS DISEASES. 



capable of inducing it ; and one reason for the indifference which 

 has been shown in respect to its ravages is to be found in the 

 belief in its spontaneous origin, an idea which arises out of the 

 observations of its frequently unaccountable appearance in iso- 

 lated places. — (Professor Brown on Mouth and Foot Complaint) 

 It was at one time believed that an animal which had once 

 suffered from eczema contagiosa was guarded against another 

 attack. This, however, is a fallacy ; and it is now generally 

 believed that an animal is only once attacked during a season. 

 As a general rule this may be said to be the case, and consequently 

 a herd which has gone through the disease early in the season — 

 let that be the spring or autumn, the periods when, in conse- 

 quence of the increased movements of cattle from place to 

 place, the disease is most rife — is considered more valuable to 

 the purchaser, and worth more money in the market. This rule 

 is, however, liable to many exceptions, and it is by no means 

 impossible for the same animal to suffer from two, three, or even 

 four attacks during a period of a few months. 



The microbe of this disease has been described by Nosotti, who 

 says that in the pure liquid of the vesicle a micrococcus, easily 

 stained with the aniline dyes, is constantly found, and which he 

 has successfully cultivated and inoculated. It is both volatile 

 and fixed, and can be transmitted directly and indirectly to 

 healthy animals. Klein describes the microbes as diplococci or 

 streptococci, which sometimes form little chains with a score of 

 sections ; if grown in coagulated serum or gelatine, they pro- 

 duce thin membranes marked with fine points formed of very 

 delicate globules, and, by mixing these cultures with food, he has 

 produced the disease in sheep, but subcutaneous inoculations 

 have failed to have any effect. The blood corpuscles are very often 

 stellate or star-like in form, and rapidly change to their natural 

 circular shape ; there is, however, no speciality in this as regards 

 the blood of cattle, as the same thing occurs in splenic apoplexy, 

 rinderpest, and even when an animal is apparently in a healthy 

 condition. Professor Brown attaches some importance to the 

 presence of vibriones, bacteria, and monads, which are found 

 in the discharge from the eyes, saliva, and the contents of the 

 vesicles. The milk also contains these bodies, and upon this 

 head Professor Brown is very clear and distinct. He says — 

 " Milk from cows affected with foot-and-mouth disease acts 

 energetically upon young animals to which it is given warm. 



