activity of the child's waking hours must be counterbalanced by ample periods of entire rest. Habits of prolonged profound sleep are said to be the best investment against mental instability and insanity; yet parents permit a constant loss of from two to four hours' sleep each night throughout the long period of immaturity.[124] Our newspapers and lunatic asylums bear evidence to the price paid for this now inexcusable carelessness. Many more examples might be given of similar fallacies which apply to later periods of life. How soon will a loving daughter allow herself to learn that the consumption of large quantities of highly nutritious food will not make for the prolongation of an aged parent's life? The fact that abstemiousness and rigid conformity to the "simple life" are not coincidents of longevity, but contributory to it, should be now common knowledge. When will the day come that the fact will be accepted that alcohol does not warm and protect the consumer, but actually lowers the temperature, and by this means, in cold weather, renders him a more ready prey to the effects of exposure. When will the value of good work cease to be measured by the exhaustion it brings about or the breakdown to which it conduces? Is it not, time that the housewife should be abashed rather than self-commiserating when a bad cold runs through her household, for observation of certain elementary principles of disinfection would go far to avert such a catastrophe? When will the fallacy be destroyed which gauges the strength of a disinfectant by the pungency of its odour? The knowledge now available on these and many other points only awaits assimilation by the housekeepers of the empire, to serve as a powerful lever by which to raise the standard of health in its every part. XVI. HOME LIFE AN IMPORTANT SPHERE FOR SANITARY SCIENCE The urgent call for a more intimate acquaintance with these tenets of domestic sanitary science calls for no further examples, though at the risk of wearying the reader one or two more may be selected to illustrate their claims upon every member of a household.