Wherever any source of pollution of school communities occurs, it must be at once and effectively detected, and some artificial elements must be introduced into the environment. In other words, there must be a system of moral orthopedics. Garofalo's[16] new term and principle of "temibility" is perhaps of great service. He would thus designate the quantum of evil feared that is sufficient to restrain criminal impulsion. We can not measure guilt or culpability, which may be of all degrees from nothing to infinity perhaps, but we can to some extent scale the effectiveness of restraint, if criminal impulse is not absolutely irresistible. Pain then must be so organised as to follow and measure the offense by as nearly a natural method as possible, while on the other hand the rewards for good conduct must also be more or less accentuated. Thus the problem of criminology for youth can not be based on the principles now recognised for adults. They can not be protective of society only, but must have marked reformatory elements. Solitude[17] which tends to make weak, agitated, and fearful, at this very gregarious age should be enforced with very great discretion. There must be no personal and unmotivated clemency or pardon in such scheme, for, according to the old saw, "Mercy but murders, pardoning those who kill"; nor on the other hand should there be the excessive disregard of personal adjustments, and the uniformitarian, who perhaps celebrated his highest triumph in the old sentence, "Kill all offenders and suspects, for God will know his own," should have no part nor lot here. The philosopher Hartmann has a suggestive article advocating that penal colonies made up of transported criminals should be experimented upon by statesmen in order to put various theories of self-government to a practical test. However this may be, the penologist of youth must face some such problem in the organization of the house of detention, boys' club, farm, reformatory, etc. We must pass beyond the clumsy apparatus of a term sentence., or the devices of a jury, clumsier yet, for this purpose; we must admit the principle of regret, fear, penance, material restoration of damage, and understand the sense in which, for both society and for the individual, it makes no practical difference whether experts think there is some taint of insanity, provided only that irresponsibility is not hopelessly complete.