from ἡμέρα, "a day;" a diary fever, or a fever of one day's continuance only. In this case, such a heat as attends an excess of wine, a pulse somewhat full and quick, but soft and regular, a slight headache, a nausea, and reflexions, are all the symptoms, and which terminate without any sensible evacuation. If it continue unto the third day, it is not a diary fever; and if the constitution is very dry, an hectic is to be dreaded.

the Day fly, in zoology, a genus belonging to the order of neuroptera. It has no teeth or palps; there are two large protuberances above the eyes; the wings are erect, the two hind ones being largest; and the tail is bristly. These flies, who take their name from the shortness of their life, are distinguished into several species. Some live several days, others do not take flight till the setting of the sun, and live not to see the rising of that luminary. Some exist but one hour, others but half that time; in which short period they comply with the call of nature. With respect to those who live several days, there is a peculiarity observed, incident to themselves alone. They have to cast off one flough more, an operation which sometimes takes 24 hours to complete. To bring this about, they cling fast to a tree. The ephemerae, before they flutter in air, have in some manner been fishes. They remain in the states of larva and chrysalis for one, two, or three years. The chrysalis only differs from the larva by there being observable small fringes of hair, which, when put into motion, serve them as fins. Nothing can be more curious than the plying of those little oars in the water. Their abdomen is terminated, as well as in their state of flies, by three threads. These larvae scoop themselves out dwellings in the banks of rivers; and they are small tubes made like siphons, the one serving for an entrance, the other affording them an outlet. The banks of some rivers are often perforated with them. When the waters decrease, they dig fresh holes lower down, in order to enjoy their element the water. The season and hour when the chrysalids of the different species of the ephemera turn into flies, maintain a kind of regularity. The heat, the rise or fall of the waters, accelerate, however, or postpone their final display. The ephemerae of the Rhine appear in the air two hours before sunset. These flies are hatched almost all at the same instant in such numbers as to darken the air. The most early of those on the Marne and Seine in France do not begin to fly till two hours after the setting of the sun, towards the middle of August. They are seen fluttering and sporting on the brink of their tomb. The glare of light attracts them, round which they perform a thousand circles with amazing regularity. Their coming together for the purpose of generation can only be furnished, the shortness of their life requiring that all its functions should be proportionable to their duration. Some naturalists have been of opinion, that the males impregnated the eggs after the manner of fishes. The females, by the help of the threads of their tail and the flapping of their wings, support themselves on the surface of the water, and in that almost upright situation drop their eggs in clutters. One single female will lay 700 or 800 eggs, which sink to the bottom. The larvae escape from the voraciousness of the fishes, set about the construction of habitations to shelter them from every kind of danger. When the flies have propagated, they are seen to die and fall by heaps. The land and water are strewed with them to a considerable thickness. The fishermen consider these multitudes of destroyed insects as manna for the fishes.