Plain Facts for Old and Young by John Harvey Kellogg

5. _Lassitude_ is as unnatural for a child as for a young kitten. A

healthy child will be active, playful, full of life and animal spirits. If a young child manifests indisposition to activity, a dislike for play, lifelessness and languor, suspect his habits, if there is no other reasonable cause to which to attribute his unnatural want of childish sprightliness.