Eight Hundred Leagues on the Amazon

It contained about a hundred of these lines, with the letters at even distances, and undivided into words.
Do not forget to set image alt text!

The man who held in his hand the document of which this strange assemblage of letters formed the concluding paragraph remained for some moments lost in thought.

It contained about a hundred of these lines, with the letters at even distances, and undivided into words. It seemed to have been written many years before, and time had already laid his tawny finger on the sheet of good stout paper which was covered with the hieroglyphics.

On what principle had these letters been arranged? He who held the paper was alone able to tell. With such cipher language it is as with the locks of some of our iron safes–in either case the protection is the same. The combinations which they lead to can be counted by millions, and no calculator’s life would suffice to express them. Some particular “word” has to be known before the lock of the safe will act, and some “cipher” is necessary before that cryptogram can be read.

He who had just reperused the document was but a simple “captain of the woods.” Under the name of “Capitaes do Mato” are known in Brazil those individuals who are engaged in the recapture of fugitive slaves. The institution dates from 1722. At that period anti-slavery ideas had entered the minds of a few philanthropists, and more than a century had to elapse before the mass of the people grasped and applied them. That freedom was a right, that the very first of the natural rights of man was to be free and to belong only to himself, would seem to be self-evident, and yet thousands of years had to pass before the glorious thought was generally accepted, and the nations of the earth had the courage to proclaim it.

In 1852, the year in which our story opens, there were still slaves in Brazil, and as a natural consequence, captains of the woods to pursue them. For certain reasons of political economy the hour of general emancipation had been delayed, but the black had at this date the right to ransom himself, the children which were born to him were born free. The day was not far distant when the magnificent country, into which could be put three-quarters of the continent of Europe, would no longer count a single slave among its ten millions of inhabitants.

From https://www.classicreader.com/book/1840/1/