electro-chemically till they knew the element that, combining with this bacterial food, would neutralise its attraction and yet leave the body as efficient and healthy as before; in short, they could prescribe the antidote to every disease that had ever enfeebled any portion of their system. Diseases were nothing else than the infinitesimal life of space fixing itself, after an eternity of detachment and attenuation, upon a living soil fat with the elements of attraction and nourishment and yet too feeble to hold out against its ravages. They drew an analogy from their old agriculture; weeds were nothing but plants finding at last the conditions which would give them the victory in the struggle for existence and would enable them to grow so rapidly and luxuriantly as to choke all neighbours; and their old science of earth culture set them on the way to a true medical science. They had watched with their clirolans the selective processes of the roots of each weed, and by various analysers had found the combination of elements in the soil and air by which it overcame its rivals; they then discovered the special component which, uniting with its food, would deprive the weed of its nutritive powers. Thus were they able to encourage or discourage on any soil any growth they might select. But agriculture had been completely superseded by their later chemistry. The best thing it had left to their civilisation was the cue it gave by analogy to their true science of therapeutics. How minute and detailed was their study of the infinitesimal life of the universe, I could not have imagined without having seen it in practice. They had advanced so far with their clirolans and vimolans that they were now discovering a still more infinitesimal world which was parasitic on microscopic life. There had been elements and effects at times discoverable in their therapeutic problems that disturbed the certainty of their conclusions and solutions. Again and again their foresights had been mistaken, their calculations thrown out. Most often was this the case on the borderland of the moral world. They had known in their own far past history, and in the more recent history of the other islands of the archipelago, the demoralising effect of epidemics and plagues, especially of a new and vigorous type. For a time the people who came within the influence of the disease seemed to return almost to savagery. And yet every plague differed slightly from every other in its moral results. One made the whole population thieves; another made them liars; a third stirred up a fury of lust; a fourth delivered over the soul to despair of life, and a fifth to disloyalty and intrigue. When once their attention was called to this widespread demoralisation after an epidemic, they began to watch the effect of individual illnesses on the mind; and in every case there were results, emotional, moral, or intellectual, that were not to be accounted for