The following is excerpted from an Amazon.com book review for Travels in the Interior Districts of Africa by Mungo Park and James Rennell.

“Mungo Park was the first European to visit the Niger River basin in 1796. He resolved, once and for all, a debate that had European cartographers and geographers confused for centuries.

His initial journey (1795-1797) was a tale of tremendous personal hardship and suffering, but triumph in the end. After returning to Scotland in 1798, he became acquainted with Sir Walter Scott. They became close friends, and it was Sir Walter Scott who convinced him to return to Africa to uncover the secret of the mouth of the Niger River.

In 1805 he convinced the British government, in the middle of a war against Napoleon, to send another expedition to seek out the mouth of the Niger. With 100 officers and men he set out, retracing his earlier steps. The journey was filled with personal tragedy and heroism. After arriving on the Niger, he built a boat, named the Joliba, and traveled down the river. During the course of his journey he met and traded with the many kingdoms that lined the river. However, he also incurred the wrath of many local kings and chiefs who believed that he was cheating them.

Near the town of Bussa (now covered by a huge dam), Mungo Park met his unexpected end. For many years it has been assumed that he was attacked by hostile natives seeking to rob him. In fact it may have been due to the fact that he just failed to navigate the river.”

Excerpted from the text of the book, originally published in 1797:

...they supply the inhabitants of the maritime districts with native iron, sweet-smelling gums, frankincense, and a commodity called shea-toulou, which, literally translated, signifies tree-butter. This commodity is extracted from the kernel of a nut by boiling the nut in water...

The extract has the consistency and appearance of butter ; and is an admirable substitute for it. It is an important staple in the food of the natives and therefore the demand for it is great. ...

The people were everywhere employed in collecting the fruit of the shea trees. These trees grow in great abundance all over this part of Bambarra. They are not planted by the natives, but are found growing naturally in the woods ; and in clearing wood land for cultivation, every tree is cut down but the shea.

The tree itself very much resembles the American oak ; and the fruit, from the kernel of which, being first dried in the sun, the butter is prepared by boiling the kernel in water, has somewhat the appearance of a Spanish olive.

The kernel is enveloped in a sweet pulp, under a thin green rind.

The butter produced from it, besides the advantage of its keeping the whole year without salt, is whiter, firmer, and, to my palate, of a richer flavor than the best butter I ever tasted made f rom cow's milk. The growth and preparation of this commodity seem to be among the first object of African industry in Bambarra and the neighboring states; and it constitutes a main article of their inland commerce. ...

In a little time the “Douty” sent for me, and permitted me to sleep in a large balloon, in one corner of which was constructed a kiln for drying the fruit of the shea trees ; it contained about half a cart-load of fruit, under which was kept up a clear wood fire. I was informed that in three days the fruit would be ready for pounding and boiling, and that the butter thus manufactured is preferable to that which is prepared from fruit dried in the sun...