recurrence of the process, unless under circumstances of impaired tone, the result of weakened digestion or climatic derangement. _Malaria_.--Compared with Bengal and the Dekkan, the climate of Ceylon presents a striking superiority in mildness and exemption from all the extremes of atmospheric disturbance; and, except in particular localities, all of which are well known and avoided[1], from being liable after the rains to malaria, or infested at particular seasons with agues and fever, a lengthened residence in the island may be contemplated, without the slightest apprehension of prejudicial results. These pestilential localities are chiefly at the foot of mountains, and, strange to say, in the vicinity of some active rivers, whilst the vast level plains, whose stagnant waters are made available for the cultivation of rice, are seldom or never productive of disease. It is even believed that the deadly air is deprived of its poison in passing over an expanse of still water; and one of the most remarkable circumstances is, that the points fronting the aerial currents are those exposed to danger, whilst projecting cliffs, belts of forest, and even moderately high walls, serve to protect all behind them from attack.[2] In traversing districts suspected of malaria, experience has dictated certain precautions, which, with ordinary prudence and firmness, serve to neutralise the risk--retiring punctually at sunset, generous diet, moderate stimulants, and the daily use of quinine both before and after exposure. These, and the precaution, at whatever sacrifice of comfort, to sleep under mosquito curtains, have been proved in long journeys to be valuable prophylactics against fever and the pestilence of the jungle. [Footnote 1: Notwithstanding this general condition, fevers of a very serious kind have been occasionally known to attack persons on the coast, who had never exposed themselves to the miasma of the jungle. Such instances have occurred at Galle, and more rarely at Colombo. The characteristics of places in this regard have, in some instances, changed unaccountably; thus at Persadenia, close to Kandy, it was at one time regarded as dangerous to sleep.] [Footnote 2: Generally speaking, a flat open country is healthy, either when flooded deeply by rains, or when dried to hardness by the sun; but in the process of dessication, its exhalations are perilous. The wooded slopes at the base of mountains are notorious for fevers; such as the _terrai_ of the Nepal hills, the Wynaad jungle, at the foot of the Ghauts, and the eastern side of the mountains of Ceylon.]