The methods now in use to prevent physical disease may be applied to a considerable extent in preventing mental disease. They include the dissemination of knowledge of hygiene and sanitation, prompt treatment of incipient diseases, segregation of those suffering from contagious diseases, and immunization of those liable to exposure to pathogenic germs. Another line of attack consists in safeguarding the public from injurious food and artificial beverages and from polluted air and water. The abolition of the liquor traffic and the movement to check the spread of syphilis are examples of effective work along these lines.

Economic and social stresses should be lightened for those unable to withstand them. It is far easier to relieve an overburdened man by taking part of his load than to wait until he is exhausted and then carry him together with his burden. Physicians, parents, and teachers should be alert to detect signs of mental disorder and apply the proper remedy before complete breakdown occurs.

Mental clinics and social workers are of large service in giving treatment in incipient cases. Many a case of mental disease is averted by adjusting the environment to the individual and by giving him a clear understanding of his mental difficulties and the best methods of meeting them. Wide extension of mental-clinic work is clearly indicated.

The new science of mental hygiene is teaching us that individuals with unfavorable heredity may do much to overcome their constitutional tendencies and to preserve their mental health. It is of the highest importance, therefore, that mental hygiene be taught and practiced in the public schools along with physical hygiene.

A decade ago sterilization of defectives was widely advocated and laws making provision for it were passed in several states. These measures have availed little because they have not been supported by active public sentiment. Judging from the present outlook, we cannot hope that sterilization will soon be an effective means of preventing mental disease.

Segregation of the mentally defective and epileptic is the prevailing method of limiting procreation among these classes. Its eugenic value is beyond question, but the enormous cost limits its application. As a rule the mental defectives and epileptics cared for in institutions are of low grade. These, if left at liberty, would multiply far less than those of higher grade. Much is to be hoped from the colony plan of segregating mental defectives, as colonies care for high-grade defectives and under wise management become self-supporting and may be increased without limit.

A new departure has been made by the state of New York in establishing a separate institution for defective delinquents at Napanoch. This troublesome group has been a serious problem in the jails and prisons of the state, and heretofore there has been no satisfactory way of dealing with them. Their segregation should have large eugenic significance.

Segregation of the insane is fairly complete, but as only about one-fourth of the first admissions are under thirty years of age on admission, its value in preventing procreation in this group is not as great as would appear when only the number of patients under treatment is considered. Overcrowding and the expense of maintenance cause patients to be promptly released on improvement of their mental condition, regardless of the eugenic factors involved.

Something can be done to lessen reproduction among the unfit by enlightened public sentiment and by better marriage laws. Marriage of persons with marked intellectual or temperamental abnormalities should be entirely prohibited.

To prevent the marriage of normal persons with those carrying a neuropathic taint more knowledge of family stocks must be made available. At the present time genealogical records of the average family are woefully meager and comparatively few are available for public inspection. If we are to improve the race by better marriages, genealogical or eugenic bureaus must be established in cities and villages. Data concerning family stocks should show the defects as well as the excellencies and achievements of the individuals recorded and be available to interested parties.