GENERAL OBSERVATIONS
There are many other signs and abbreviations used in works on the various sciences. Approved modern text-books are the only safe guides to the proper use of these.
In printing dialect, slang, and colloquialisms the only general rule is to follow copy.
Such abbreviations as I've, you'll, 't'was, 't'is n't, and the like are more clearly expressed when a thin space is put between the words.
Old Style contractions should follow the original even if special sorts have to be obtained for the purpose.
Abbreviations like dept, dep't, gov't, sec, sec'y, sect'y, pres't, and treas. are indefensible. Even in letter heads and the like it is better to spell out the words in two lines.