And memorable to him likewise had been Hogarth's _Progress of the Rake_ with its few pictures; and his _Progress of the Harlot_ with its few; and his _Progress of Marriage à la Mode_ with its few; and the _Progress of Cruelty_ with its fewest of all--only four, but more than enough! And yet the stages in the progress of the rake and of the harlot and of marriage à la mode and of cruelty are infinite; and at no single stage in the progress of any one of them could you actually find either Rake or Harlot or Infidelity or Cruelty. Being portrayed as few, the world understands and finds its own account in them. So around the walls of his library there hung a series of pictures showing the progress of Medicine across the ages. The first picture represented a scene in the life of primitive man, during the period when he had long enough been man to form into hostile tribes, but not long enough to have advanced far from the boundaries of the brute. It is a battle picture: the battle is over: the survivors are gone: the dead and wounded lie about. Medicine as a human science has not yet been born; surgery has not yet separated itself from the movements of instinct. Yet there was activity among the wounded. In some of the warriors you saw such attempts in the care of their wounds as one may witness to-day in wounded birds and animals--if one is fortunate enough to be so placed as to be able to watch: there were the instinctive devices to cleanse, to protect, to alleviate: those low beginnings of the great science which you may observe to-day in your dog when he has come home after a fight with lacerated ears and slashed thighs--when he crawls under the porch to the darkest corner to keep away other dogs and light and flies; whose sole instrument of cleansing is his tongue and whose only bathing fluid is saliva. On that battle-field you saw such beginnings of surgery as to-day is practised by a bird treating its broken wing or broken leg. Thus the wounded warriors concerned themselves with their hurts--all mother-naked. Along one edge of the battle-field was a stream of running water; some had started to draw themselves toward this and had died on the way. One was stretched full alongside--a young chief of magnificent proportions and a face of higher intelligence. And out of that intelligence, as a marvellous advance in the development of man, you saw one action: he was dipping up water in the palm of his hand and pouring it upon his wound. At some moment in the history of the race there must somewhere have been that first movement of the developing animal to substitute water for saliva. That great historic moment was depicted there. It was still the Azoic Age of Medicine.