What does the word treats mean in this context? I don't think it means entertainment, food, drink etc.. Maybe it is an old usage of this word? Does it mean influencing factors or something like that?
This is the first part of the title of the first chapter of the novel "Oliver Twist" by Charles Dickens. The whole title reads:
Treats of the Place Where Oliver Twist was Born and of the Circumstances Attending His Birth
This phrase is the name of the first chapter in Oliver Twist. Let's take a look at a few other chapter names:
Source: Dickens, C. (1838). Oliver Twist.London, England; Bentley's Miscellany. http://etc.usf.edu/lit2go/50/oliver-twist/
Chapter 1: Treats of the Place Where Oliver Twist was Born and of the Circumstances Attending His Birth.
Chapter 2: Treats of Oliver Twist's Growth, Education, and Board.
Chapter 3: Relates How Oliver Twist was Very Near Getting a Place Which Would Not Have Been a Sinecure.
Chapter 11: Treats of Mr. Fang the Police Magistrate; And Furnishes a Slight Specimen of His Mode of Administering Justice.
Chapter 24: Treats on a Very Poor Subject. But is a Short One, and May be Found of Importance in this History.
Chapter 34: Contains Some Introductory Particulars Relative to a Young Gentleman Who Now Arrives Upon the Scene; And a New Adventure Which Happened to Oliver.
The examples I gave, and a few others, have chapter names that follow the pattern "Chapter XX does Y." Chapter 11, in particular has this structure twice.
So it looks like treats is being employed as a verb.
As for meaning? Treats can mean something like "provides." In modern English, it is usually used for desirable things and is usually followed by "to." (e.g. I treated the basketball team to ice cream after the game) I don't know if the convention wasn't established when Dickens wrote these chapter headings, or if he is just being colorful, but it looks like your quote means:
Chapter One describes the place where Oliver Twist was born.
Also, with acknowledgement to a comment by @Bob Jarvis: Dictionary.com's 9th definition for treat gives an example that uses treats + of: "to deal with a subject in speech or writing; discourse: (example) a work that treats of the caste system in India."
The word treats can mean "discusses a subject". As in, "This book treats the question of how World War 2 started." I think this usage is becoming out of date, you mostly see it in older books.
So in this case, the chapter discusses where Oliver Twist was born.
See, for example, thefreedictionary.com, definitions 3 and 4.
"Treat", or better, "treat of" is the verb to the noun "treatise", which OALD defines as:
treatise (on something) (formal)
a long and serious piece of writing on a particular subject
Definitions on this specific meaning of "treat" are a bit harder to find. Collins dictionary gives the definition:
treat (verb)
8. (intransitive) usually foll by of (formal)
to deal (with), as in writing or speaking
So a more colloquial title for Dicken's first chapter could be:
"Describing the Place Where Oliver Twist was Born and of the Circumstances Attending His Birth"
