O. S. and N. S.: On consultation with several specialists I have concluded that the abbreviations O. S. and N. S. relate to the difference between the old Julian calender used in England and the Gregorian calender which was the standard in Europe. In the mid 18th century it is said that this once amounted to a difference of eleven days. To keep track of the chronology of letters back and forth from England to France or other countries in mainland Europe, Chesterfield inserted in dates the designation O. S. (old style) and N. S. (new style).
Chesterfield demonstrates his classical education by frequent words and sometimes entire paragraphs in various languages. In the 1901 text these were in italics; in this etext edition I have substituted single quotation marks around these, as in 'bon mot', and not attempted to include the various accent marks of all the languages.
I have appended a list of phrases extracted from the letters as an index pointing to thoughts of particular interest to me. These are of course without page designations in this plain text format. After downloading this file to any word processing program a simple search or find operation