This section is from the book "Two Years' Course In English Composition", by Charles Lane Hanson. Also available from Amazon: Two Years' Course In English Composition.
XXXII. Brackets inclose insertions whose connection with the text is slight. They are seldom required except in quoted matter, where, to make the author's meaning clear, it is sometimes necessary to insert explanatory words in brackets.
It [a great university] is resorted to in most countries, notably in our own country, alike by rich and poor, by the children of the educated and the uneducated - in short, by the children of families of all sorts and conditions.
116. Write a theme on any subject you please. See whether the dash is of service to you in any of your sentences.
117. Exchange papers and consider whether the dash has been used correctly, or might be used to advantage.
 
Continue to: