_Mode of Infection._--As this disease is one that is due to a specific germ it is obvious that it cannot exist without the presence of this organism; the malady is therefore infectious, and must necessarily be to a certain extent contagious, notwithstanding the fact that it is generally thought not to be so. The reason that the affection has not been thought to be contagious may be explained by the following facts: Recent investigation has shown that in many, if not all, instances of this disease, the germ may be found in the nose and throat, where, as has already been explained, it sets up a condition resembling an ordinary cold. In all probability the infection takes place in the nasal cavity first, and the germ ultimately finds its way to the coverings of the brain. Now there is every reason to believe that in many, and probably in a great majority of instances, the germ goes no further than the mucous membrane of the nose, and the patient merely has as a consequence what he considers an ordinary cold. It is clear, however, that if another individual, who was very susceptible to this germ, should contract the disease from this person, he might have the meningeal form of it. In other words, it is probably true that the vast majority of people who are attacked by this organism simply get colds as a consequence, and only now and then does a person get meningitis as a result. This explains why the disease does not ordinarily appear contagious. The facts above stated are of much importance in combating the spread of this disease. People who are exposed to those having meningitis should be exceedingly careful not to get upon their persons any of the secretions that come from the patient, and during periods of epidemics those who observe a bad cold coming on should promptly consult their physicians, and do everything to prevent the development of all catarrhal conditions in their noses. During epidemics persons with colds should be very careful not to allow other people to become infected from them. As cold and wet are undoubtedly predisposing causes to colds it is well for everyone to shun such exposure during periods when meningitis is prevalent; debilitating influences, such as alcoholic excess and lack of sleep, should also be avoided. HYDROPHOBIA. This disease, as it occurs in man, is practically always conveyed by the bite of some animal, the dog being the usual offender. The poison is present in the saliva of the diseased animal and is transmitted through wounds made by its bite. As observed in the dog, there are two types of the disease,--one the "furious," the other the "paralytic."