In many important points the habitual or long continued use of chloral differs from that of opium or morphine, viz:
1. Many persons take it for years without any obvious ill effect.
2. Its continued use is not so liable to be followed by a morbid craving for it as for morphine or opium.
3. The habit once formed is, in the majority of instances, easily broken.
4. An abrupt change from chloral to some other narcotic is often made.
As regards the first and second propositions the following facts may be taken into account:—
Dr. W. M. Compton,[45] Medical Superintendent, Insane Asylum, Jackson, Miss., says that he has given twenty to thirty-grain doses of chloral hydrate nightly, for years, to noisy patients, without observing any ill effects. Dr. J. H. Nordlin,[46] of Rome, Ga., has given it in combination with bromide of potassium, capsicum and ammonia, in asthma, for a long time, without any ill effects.
A correspondent of the London Lancet,[47] a medical man, says that, for sleeplessness, he has been obliged to take twenty-grain doses of chloral at bedtime, for upward of four years, without any bad consequences whatever.
Dr. J. G. Thornley[48] has used chloral in the treatment of insane persons, continuing its use for from six months to two years, without any ill effects.