Of the infectiousness of nervous disease it seems almost useless at present to speak, for few will listen. Probably the malady will, for some time to come, continue to be spread abroad by those who suffer from it, as certainly as leprosy is spread by the leper. The early symptoms not being readily observed and recognised by the uninitiated, great mischief can be wrought while all around remain unconscious of the impending disaster. To young persons, and to those who inherit a predisposition to nerve-weakness, the danger of infection is specially great. Moreover, the predisposed often aid one another in the development of the malady, a fact which is sufficiently proved by observation of families exhibiting neurotic tendencies. It has been fully recognised that imperfect recovery from some attack of illness is a frequent cause of neurasthenia. It is not fully recognised that the cause is usually a preventible one. A very common blunder is generally at the root of the mischief. It is thought necessary to hurry on the convalescent lest she should “drift into chronic invalidism,” as the saying goes. The result is that the patient recovers to a certain extent, only to fall a victim later to chronic nervous weakness. Patients who are making a natural and healthy recovery are over-eager to exert themselves, and require to be kept back. Should this eagerness not be manifested, it is a mistake to say that the patient must be roused in order to preserve her from neurasthenia. Neurasthenia is already there, and unless the building up of the nervous system go hand in hand with the patient’s exertions, those exertions will assuredly be productive of harm. Unfortunately the patient is frequently removed from the watchful care of the doctor and the nurse just as watchful care is most urgently needed.