An essay on yellow fever : comprising the history of that disease, as it appeared in the island of Antigua in the years 1835, 1839, & 1842, with an appendix continuing the history to 1853 / by Thomas Nicholson.

  • Nicholson, T. J.
Date:
1856
Catalogue details

Licence: Public Domain Mark

Credit: An essay on yellow fever : comprising the history of that disease, as it appeared in the island of Antigua in the years 1835, 1839, & 1842, with an appendix continuing the history to 1853 / by Thomas Nicholson. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

    19/34
    creeks and bays, who&e oozy waters maintain th^ growth of impenetrable thickets of the different species of mangrove, and are the fertile sources of malaria. In a geological point of view, the island comprises thiee distinct formations of the tertiary class, of which the most su- perficial beds occupy the northern and eastern divisions. These consist of a calcareous marl, and coarse sandstone, in- terspersed with masses of a tolerably compact shell limestone. On the surface are found a great varietv of marine exuvia?, analogous to those which at present inhabit the surrounding geas; as astrea, meandrinae, tubipora, etc. The surtarc of this district is exceedingly broken and undulated, consisting of a series of round-backed hills of no great elevation, covered with a light arid soil. The sides of the hills and intervening valleys are highly cultivated, and produce a rapid growth when duly favoured with rain. The mountainous district, forming the southern and wen- err, divisions, is composed of rocks of the newest floetz trap for- mations, as waeke, porphyry, trap breccia, ampv : laloid, and some spherical masses of basaltic green-stone Some of these mountains rise with couical summits to the height of 800 to 1,000 feet ; others, of the same elevation, are mote rounded and less precipitous, affording a good soil for the sugar-cane even on the tops. They are intersected by beautifully roman- tic valleys ; and the abrupt sides of the mountains are cloth- ed with the verdant foliage of a great variety of herbs, and trees, and twining shrubs. The intermediate district is occupied by a series of argilla- ceous strata of varied characters, which dip at a considerable angle to the north and north-east, and extend across the is- land from Willoughby Bay on the south-east to St. John's in the north west. The northern limit of this district is formed by a zone of low land, which at no very distant period, appears to have been submerged, and even now, after heavy rains. i3 readily converted into a marsh. It rises with a gentle ^fcli- Oa/ vity towards the south and southwest, where it presents a precipitous escarpment, and is divided from the trap forma- tion by a ravine, in which are pools of stagnant water, and a slu^lsh stream which runs towards the west, through a beautifully luxuriant plain.