Use single quotes (') for phrases.
Something kept telling me to go into Mexico and bury it, he wrote ruefully
The Important Features of Nicotine Intoxication Restlessness, psycho-motor agitation, anxiety, headache, palpitations or paresthesias, GI symptoms such as nausea, vomiting, abdominal cramps, burning sensation in the mouth, and salivation
As the author points out, Magistrates, medical men and politicians who were confident that they would never be stabbed to death in a drunken brawl knew that they could still be poisoned by a daughter or a wife or a cook, and felt threatened and vulnerable. Stratmanns portrait of the age of arsenic (by far the most frequently used poison) is more than a string of grisly tales, and more relevant to our age than you might think