“I may here advert to a belief which appears to be widely entertained, viz. that fish contains certain elements which adapt it in an especial manner to renovate the brain, and so to support mental labour. There is no foundation whatever for this view: the value of fish to the brain-worker is due simply to the facts already referred to, viz. that it contains, in smaller proportion than meat, those materials which, taken abundantly, demand more physical labour for their complete consumption, and which without this produce an unhealthy condition of body, more or less incompatible with the easy and active exercise of the functions of the brain.”