HYDROPHOBIA 191 



depression, a tendency to lick objects, and paralysis of the muscles, which close 

 the jaws. As a consequence of the paralysis, the lower jaw drops, the animal is 

 unable to close the mouth, the tongue hangs out and an abundance of saliva 

 escapes. The mucous membrane of the mouth becomes dry, discolored, and cov- 

 ered with dust. The animal remains quiet, does not respond to provocations, and 

 appears to understand its helplessness. As Bouley has said, the animal can not 

 bite and does not desire to bite. 



"When dumb rabies follows a period in which the animal has been affected 

 with the furious form, the desire and tendency to bite may be retained even 

 after the jaw is paralyzed. 



"The course of the disease is short, death usually occurring in from two to 

 four days. 



"The dumb form of rabies is very common, and many persons know it as 

 'drop jaw' who have no idea of its true nature. 



"Many of the common mistakes with reference to rabies arise from an imper- 

 fect knowledge of the symptoms. It is on this point that there is greatest need 

 of educational work. Bouley has most earnestly warned us to 'distrust a dog 

 when it shows signs of illness; every sick dog should as a rule be suspected; more 

 particularly distrust a dog when it becomes dull, morose and seeks for solitude, 

 which appears not to know where to rest, which is always on the move, prowling, 

 snapping 'at the air, and suddenly barking at nothing when all around is perfectly 

 still, whose countenance is somber, and only assumes its usual animated expres- 

 sion by brief starts; beware of the dog that seeks and scrapes incessantly, and 

 exhibits aggressive movements against phantoms; and, finally, beware, above all, 

 of the dog which has become too fond of you, and is continually endeavoring to 

 lick the hands or face." 



THE PERIOD OF INCUBATION OF RABIES. 



The period of incubation of a contagious disease is the time which elapses 

 between the inoculation or exposure and the appearance of the first symptoms. 

 With rabies this period varies remarkably. It may be as short as six or seven 

 days, and it occasionally exceeds one hundred days. In rare cases it has been 

 reported on good authority that a year, or even fourteen months, elapsed between 

 the time the animal was bitten and the time when the disease manifested itself. 

 The majority of cases develop in from three to seven weeks. 



During the greater part of the period of incubation the infected animal is 

 healthy, and would not cause disease in any animal or person which it bites. The 

 saliva may become virulent, however, two or three days before the appearance of 

 the iirst symptoms, and any animal or person bitten after the contagion has con- 

 taminated the saliva is, of course, liable to contract the disease. 



There is a very erroneous and rather stupid belief, quite common, to the effect 

 that if a dog bites a person and becomes mad at any time thereafter the person so 

 bitten will contract hydrophobia. This fallacy may have arisen from some 

 instance in which a person had been bitten within a few days of the appearance 

 of the symptoms of disease in the dog, and when the saliva was already virulent. 

 However this may be, it is perfectly certain that a dog can not convey this 

 disease when he- does not have it or before he has himself contracted it. if, 

 therefore, a dog does not show symptoms of rabies within a week from the time 

 the bite is inflicted there is no danger of the person contracting the disease. The 

 only possibility of an exception to this rule is the very doubtful one, that in 

 extremely rare instances a dog may have rabies and recover from it without 



