264 APPLIED BACTERIOLOGY 



Post-mortem Appearances. — The tongue and mucous mem- 

 brane of the mouth will be found of a dark, blackish colour. 

 The glands are enlarged and congested, the tonsils inflamed, 

 and the vessels of the epiglottis injected. The lungs are 

 congested, while the stomach may contain all kinds of foreign 

 matters, such as rags, straw, pieces of leather, wood, hair, 

 and the like. The brain and spinal cord are congested. 

 To establish the diagnosis beyond doubt it is necessary to 

 inoculate a rabbit under the dura mater in the manner 

 described later in this chapter with a broth emulsion of a 

 small piece of a dog's spinal cord. After positive results 

 have been obtained by this procedure no doubt can be 

 entertained as to the true nature of the disease. The test 

 animal will exhibit symptoms of rabies within twelve days 

 if the suspected animal really suffered from the disease.' 

 The test animal, in the case of the dog, may exhibit either 

 the furious state, in which it barks in a peculiar manner 

 and is very aggressive, or it may exhibit the dumb or 

 paralytic condition ; both of these conditions end in 

 death. 



Incubation Period. — The incubation period in a dog which 

 has been bitten by a mad one will be found to be from 

 about six to eight weeks, though it may extend to six 

 months. 



In man, in the majority of cases, the disease usually 

 develops in from eight days to six weeks up to six months, 

 a few cases being quoted where longer periods of incubation 

 have occurred. The incubation period, as applied generally 

 to man and animals, of course depends considerably on the 

 nature of the bites received — the graver the wounds, the 

 shorter the period of incubation. 



Treatment. — In man, all that can be done locally is 

 immediate cauterisation, the wound being well opened up 

 and a hot iron or strong nitric acid used freely. The effect 



