There are few cases more distressing for a physician to witness, or difficult for him to manage, or in which he incurs greater risks or responsibilities, than those varieties of insanity in which refusal of food is a marked and prominent feature. To fix the exact moment when exhausted nature must be replenished; to determine when persuasion shall be given up and force, as a last resort, had recourse to; to estimate the quantity and quality of food required; to distinguish where medicines are life or death; to recognise the variety of medicine necessary to meet the requirements of the particular case; and, lastly, to decide on the mode of administration, are all matters of such primary importance, and require such a sound knowledge and extended experience, that one might deprecatingly exclaim, Nemo tenetur ad impossibile.