Page:Travels to Discover the Source of the Nile - In the Years 1768, 1769, 1770, 1771, 1772, and 1773 volume 4.djvu/511

 journey down the desert, to which Heaven, in pity to mankind, has confined it, and where it has, no doubt, contributed to the total extinction of every thing that hath the breath of life. A thermometer graduated upon this scale would exhibit a figure very different from the common one; for I am convinced by experiment, that a web of the finest muslin, wrapt round the body at Sennaar, will occasion at midday a greater sensation of heat in the body than the rise of 5° in the thermometer of Fahrenheit.

At Sennaar, from 70° to 78° in Fahrenheit's thermometer is cool; from 79° to 92° temperate; at 92" begins warm. Although the degree of the thermometer marks a greater heat than is felt by the body of us strangers, it seems to me that the sensations of the natives bear still a less proportion to that degree than ours. On the 2d of August, while I was lying perfectly enervated on a carpet, in a room deluged with water, at twelve o'clock, the thermometer at 116°, I saw several black labourers pulling down a house, working with great vigour, without any symptoms of being at all incommoded.

The diseases of Sennaar are the dysentery, or bloody flux, fatal in proportion as it begins with the first of the rains, or the end of them, and return of the fair weather. Intermitting fevers accompany this complaint very frequently, which often ends in them. Bark is a sovereign remedy in this country, and seems to be by so much the surer, that it purges on taking the first doze, and this it does almost without exception. Epilepsies and cirrhosis livers are like wise very frequent, owing, as is supposed, to their defeating or diminishing perspiration, or stopping the pores by constant