You will be brought to acknowledge that the logical faculty has infinitely more to do with poetry than the young and the inexperienced, whether writer or critic, ever dreams of.  Indeed, as the materials upon which that faculty is exorcised in poetry are so subtle, so plastic, so complex, the application of it requires an adroitness which can proceed from nothing but practice, a discernment which emotion is so far from bestowing that at first it is ever in the way of it.  Here I must stop:  only let me advert to two lines: 

    ’But shall despondence therefore blench my brow,
    Or pining sorrow sickly ardor o’er.’

These are two of the worst lines in mere expression.  ‘Blench’ is perhaps miswritten for ‘blanch;’ if not, I don’t understand the word. Blench signifies to flinch.  If ‘blanch’ be the word, the next ought to be ‘hair.’  You cannot here use brow for the hair upon it, because a white brow or forehead is a beautiful characteristic of youth.  ’Sickly ardor o’er’ was at first reading to me unintelligible.  I took ‘sickly’ to be an adjective joined with ‘ardor,’ whereas you mean it as a portion of a verb, from Shakspeare, ’Sicklied o’er with the pale cast of thought.’  But the separation of the parts or decomposition of the word, as here done, is not to be endured.

Let me now come to your sister’s verses, for which I thank you.  They are surprisingly vigorous for a female pen, but occasionally too rugged, and especially for such a subject; they have also the same faults in expression as your own, but not, I think, in quite an equal degree.  Much is to be hoped from feelings so strong, and from a mind thus disposed.  I should have entered into particulars with these also, had I seen you after they came into my hands.  Your sister is, no doubt, aware that in her poem she has trodden the same ground as Gray, in his ’Ode upon a distant Prospect of Eton College.’  What he has been contented to treat in the abstract, she has represented in particular, and with admirable spirit.  But again, my dear Sir, let me exhort you (and do you exhort your sister) to deal little with modern writers, but fix your attention almost exclusively upon those who have stood the test of time. You have not leisure to allow of your being tempted to turn aside from the right course by deceitful lights.  My household desire to be remembered to you in no formal way.  Seldom have I parted, never I was going to say, with one whom after so short an acquaintance, I lost sight of with more regret.  I trust we shall meet again, if not [sentence cut off with the autograph].  Postscript.  Pray do not forget to remember me to Mr. Otway.  I was much pleased with him and with your fellow-traveller Mr. Nimmo, as I should have been, no doubt, with the young Irishman, had not our conversation taken so serious a turn.  The passage in Tacitus which Milton’s line so strongly resembles is not in the ‘Agricola,’ nor can I find it, but it exists somewhere.