the tropics; trade-winds gain their easterly direction from the greater velocity of the earth's surface at the line; not supplied by superior currents; supplied by decomposed water in the sun's great light; 1. Because there are no constant rains in the tract of the trade-winds; 2. Because there is no condensible vapour above three or four miles high at the line. _Monsoons and tornadoes_; some places at the tropic become warmer when the sun is vertical than at the line; hence the air ascends, supplied on one side by the north-east winds, and on the other by the south-west; whence an ascending eddy or tornado, raising water from the sea, or sand from the desert, and incessant rains; air diminished to the northward produces south-west winds; tornadoes from heavier air above sinking through lighter air below, which rises through a perforation; hence trees are thrown down in a narrow line of twenty or forty yards broad, the sea rises like a cone, with great rain and lightning. _Land and sea breezes_; sea less heated than land; tropical islands more heated in the day than the sea, and are cooled more in the night. _Conclusion_; irregular winds from other causes; only two original winds north and south; different sounds of north-east and south-west winds; a Bear or Dragon in the arctic circle that swallows at times and disembogues again above one fifteenth part of the atmosphere; wind- instruments; recapitulation. NOTE XXXIV ... VEGETABLE PERSPIRATION. Pure air from Dr. Priestley's vegetable matter, and from vegetable leaves, owing to decomposition of water; the hydrogene retained by the vegetables; plants in the shade are _tanned_ green by the sun's light; animal skins are _tanned_ yellow by the retention of hydrogene; much pure air from dew on a sunny morning; bleaching why sooner performed on cotton than linen; bees wax bleached; metals calcined by decomposition of water; oil bleached in the light becomes yellow again in the dark; nitrous acid coloured by being exposed to the sun; vegetables perspire more than animals, hence in the sun-shine they purify air more by their perspiration than they injure it by their respiration; they grow fastest in their sleep. NOTE XXXV ... VEGETABLE PLACENTATION. Buds the viviparous offspring of vegetables; placentation in bulbs and seeds; placentation of buds in the roots, hence the rising of sap in the spring, as in vines, birch, which ceases as soon as the leaves expand; production of the leaf of Horse-chesnut, and of its new bud; oil of vitriol on the bud of Mimosa killed the leaf also; placentation shewn from the sweetness of the sap; no umbilical artery in vegetables. NOTE XXXVI ... VEGETABLE CIRCULATION.