Final answer:
An essay on a nontechnical subject written in a relaxed and intimate manner and published in periodicals such as the London Magazine is known as an essay.
Step-by-step explanation:
An essay on a nontechnical subject written in a relaxed and intimate manner and published in periodicals such as the London Magazine is known as an essay. Essays are a common form of literary expression that allow authors to convey their thoughts and ideas in a personal and engaging way. They are often used to explore topics of interest or offer insights on various subjects.