God grant that the reader, emboldened and having become at present as fierce as what he is reading, find, without loss of bearings, his way, his wild and treacherous passage through the desolate swamps of these sombre, poison-soaked pages; for, unless he should bring to his reading a rigorous logic and a sustained mental effort at least as strong as his distrust, the lethal fumes of this book shall dissolve his soul as water does sugar.