For one moment we must stop to observe, that Bruce's account of the number and the effect produced by these flies is a part of his narrative which was long pointed at and ridiculed as being particularly unworthy of belief; yet the description already quoted from Denham (page 100) strongly corroborates Bruce's statement, which has also been confirmed by the testimony of the Abyssinian, Dean, who was publicly examined at Cairo by Dr. Clarke. No author has ever yet been able to impart to his reader an adequate idea of the clouds of locusts which, in some parts of the world, suddenly convert, for a hundred miles together, a green country into a brown one, by the total destruction of vegetable life. Bruce's account, therefore, of the havoc which the tsaltsalya, zimb, or fly of Abyssinia produces among living creatures, however strange it may sound in this country, does not, in the natural history of the world, stand unsupported. Why a portion of the animal and vegetable creation should be annoyed by such scourges as the zimb and the locust; why parts of the world should be disordered by hurricanes and earthquakes; and why the whole of mankind should occasionally suffer from pestilential disorders, &c., are problems which Bruce need not be called on to solve. He has merely added one to a number of facts, concerning which all we know is, that they form parts of a wise and beneficent system which it is entirely beyond our power to comprehend. Abyssinia being mountainous, lying in the middle of the torrid zone, and being subject also to the heavy periodical rains just described, the effect naturally produced by these three causes is, that the climates of the high and low country are totally different. The mountainous or high land of Abyssinia, which, it may be observed, is covered with long grass and destitute of wood, is at all times dry, cool, temperate, and healthy, and often even extremely cold; while the low, woody country, hazy, close, and insufferably hot, suffers severely from the sickness invariably produced by the excessive rains. Part of this low country, however, is not covered with wood; and, though equally hot, from being better ventilated, it is, generally speaking, healthy, while it is as productive as Egypt, and covered with the finest cattle of all descriptions. But where the waters of the rainy season, for want of descent, stagnate on the plains, these hot, swampy marshes produce no pasture, and are exceedingly unhealthy.