by mere weakness of the body or irritation of the nerves, or by the poisonous débris that the minute organisms threw off. They invented still more powerful clirolans, which revealed an intensity of life they had not imagined. The disease germs brought into the human system still more minute parasites that at once attacked the brain and the nerve-centres. In one disease these invisible vermin preferred one set of brain-cells, in another they preferred another. The therapeutic families engaged in the investigations were only just coming to classify these moral and intellectual parasites of the disease germs. Nor had they yet been able to discover any cure for these but the sympathetic proximity of strong and noble minds. The look from the eyes of some of their greatest doctors, even the touch of their hands, seemed to drive the living evil forth, or at least to attenuate and enfeeble it. The mind of the patient rose triumphant in the presence of one of these wise and healing personalities. It had been for ages the traditional maxim of polity that only the loftiest and most advanced, as well as most sympathetic natures should be allowed to specialise for the medical castes, or marry into the medical families. None were allowed to nurse the sick but the beautiful souls of the community; their mere presence seemed to strengthen the fainting heart in the struggle for life. As the mind grew strong, the ravages of the disease lessened. For now with their more powerful clirolans they found that, as the brain or nerve-centres acquired strength, the parasitic, invisible life took its way back to its original hosts and preyed on them. It was indeed one of the maxims of their community to keep the system of every individual at its highest point of vitality. A loss of exhilaration in any citizen was marked at once by his neighbours, just like a lapse into criminality in Western civilisation. It was the symptom of possible disease with all its power of contagion. The sense of active vitalisation (what we call the spirits) was the barometer of the sanitary, moral, and intellectual atmosphere, and every Limanoran was keenly sensitive to all its changes.