Anyone who is acquainted with the English and American literature of today knows weIl that a large portion of the works produced are what are called detective stories or tales of mystery. There is no being who can hold a pen but writes, and there are few who have not attempted, now and then, to write an intellectual story. When we consider them, it cannot but be astonishing that, until now, no one should have thought of writing an essay on this branch of literature or of studying its laws and its logic. But the reason is no other than that of the 2 classes of readers, (the high critical being one, and the low critical and the crowd generally the other), the first, seeing these tales mostly in the hands of mere scribblers, considers the type as of no value; and the second being pleased with them (as they are, indeed, pleased with any sort of nonsense) cares nothing for the rules, for, in its opinion, the tales are perfect.