Answer:
The topic of the passage is "The Middle East".
Step-by-step explanation:
The author's purpose for writing this passage is to describe the island of Madagascar and explain the way of life of the people living there.
It describes the belief of the Saracens and the fact that they worship Mahomet.
It also describes the rulers - four sheikhs who rule over the whole island and also the size of the island - 4000 miles in circumference and the fact that the people live by trade and industry.