The extreme dryness of the air in Egypt causes the visiting microbe to feel like an alien. It becomes enervated and discouraged, incapable of initiating any new and fashionable epidemics. This same air, however, seems to have a tonic effect on the flea. In no other clime is he so enterprising, so full of restless energy, so given to unexpected achievements. During a dull season, if there is a short supply of tourists, he associates with the natives. He prefers the tourist, but come what may, he is never idle. The bacillus, on the other hand, has circumscribed opportunities. Inasmuch as the entire population of the country lives along the river one might suppose that harmful germs would be bred and disseminated by the billion. Yet both natives and visitors drink from the river with impunity. "The sweet water of the Nile" it is called and even the most apprehensive travellers learn to take it after putting in about twenty drops of Scotch, so as to benumb the bacilli, if any should be present. There is an explanation of the micro-organism's failure to do very much harm in Egypt. If a bacillus living anywhere along the Nile starts for a ramble on shore he is sunstruck, and falls helpless in the sand. If he sticks to the water the monotony of travel begins to wear upon him, and after about seven miles he dies of _ennui_. If Egypt is a happy hunting ground for the flea it is likewise a paradise for the fly. If I had to be something in Egypt I should prefer to be a Mohammedan fly. This little creature, which in most countries is hounded and persecuted and openly regarded as a pest, is treated with consideration in Egypt--humoured, petted, indulged, actually spoiled. In the U.S.A. a fly is almost as unpopular as the millionaire. He is wary, fretful, and suspicious, because he knows that all humanity is joined in a conspiracy to put him out of business. If he strolls up to a pool of water, temptingly set forth in a white bowl, he finds himself a few minutes later writhing in cramps and full of corrosive sublimate. He sees what appears to be a tempting luncheon of sweets and when he starts in to serve himself he discovers that he is caught and held by the treacherous "tanglefoot" mixture. He sees a sign, "This way to the dining-room," and after passing through a long corridor he lands in a wire trap from which there is no escape. If he alights on a bald head and tries to use it as a rink somebody strikes at him and calls him names. [Illustration: _In the U.S.A. the fly is almost as unpopular as a millionaire_]