- Chad, officially the Republic of Chad, is a country located at the crossroads of North and Central Africa. The landlocked country is bordered by Libya to the north, Sudan to the east, the Central African Republic to the south, Cameroon to the southwest, Nigeria to the southwest (at Lake Chad), and Niger to the west. Chad has a population of 16 million, of which 1.6 million live in the capital and largest city of N’Djamena. With a total area of around 1,300,000 km2 (500,000 sq mi), Chad is the fifth-largest country in Africa and the twentieth largest nation by area in the world.
- And, in the last place, what above all is here worthy of observation, is the generation of the animal spirits, which are like a very subtle wind, or rather a very pure and vivid flame which, continually ascending in great abundance from the heart to the brain, thence penetrates through the nerves into the muscles, and gives motion to all the members; so that to account for other parts of the blood which, as most agitated and penetrating, are the fittest to compose these spirits, proceeding towards the brain, it is not necessary to suppose any other cause, than simply, that the arteries which carry them thither proceed from the heart in the most direct lines, and that, according to the rules of Mechanics, which are the same with those of Nature, when many objects tend at once to the same point where there is not sufficient room for all, (as is the case with the parts of the blood which flow forth from the left cavity of the heart and tend towards the brain,) the weaker and less agitated parts must necessarily be driven aside from that point by the stronger which alone in this way reach it.
