The chief interest of the London newspapers to-day is centered

in the llornilly Post; which publishes a long communication addressed to the editor, detailing the facts, us far as his Lordship has been able to ascertain them, connected with the calumny on his sister, the late Lady Flora Hastings; together with numerous letters written by parties implicated iu this affair, some of which have already been laid befbre the public, and various documents, statements, and explanations.

The Marquis gives as a reason for publication in the newspapers, that he is informed, a motion on the subject in the House of Lords would be immediately silenced as an attack upon the Throne, and that there are insuperable technical difficulties to prevent him from exposing in a court of justice " the vile conduct of those who have slandered" his sister. In answer to a question, why the publication has been so long delayed, the Marquis says— "The repeated solicitations of my sister, personally to myself, and by letter to my mother, urged me, during the time it was deemed necessary she should continue at the Palare, to remain sik nt ; as, to use her own expressions, every new act of ours was visited upon her dear mistress's and her 01511 unfortunate head. I shall nut attempt to heighten the picture of this frightful tragedy. But it cannot be supposed that a sy regard for the frelings of those, be their rank and station what they may, who have sacrificed every freling of my family—who have trodden under foot every Christian principle—who have out- raged all delicacy, justice, and honour—can weigh with me. That the power of the Csart may Mr a time protect the guilty—that it may prevent that mea- sure of justice which the common law of the land 1101(1S out to the lowest sub- ject—that it may ibster and permit to bask in its sunshine the basest of slan- derers—Las, alas been too fully pros ed. But 1 base vet to learn that in this free country it can :title the voice of truth. 1 have, therefore, determined to make the public masters of the whole business, 1 v publishing the entire cone- spondense which has taken plisse on this melanchely occasion ; and 1 now cast for ever from me it subject which lyeen productive of such pain and a sxiety, fully cmt Silent of Bair:", :thy, rat the breasts of the British natiou that justice and sy cqedliy ultieh has been tienisd me in a higher quarter."

The Marquis proceeds to state, that he received a letter from his sister, dated the 20th of February last, intlirmieg him that her honour had been most basely assailed, but entering into no particulars." He was then at ln,nini2.tcn Park, but immediately went to London ; and heard from his sister " a partial outline of the disgusting truths" so well known to the public- " She said. at once, that she felt it a duty site owed to herself, her mistress, and her to submit to the inhuman trials she underwent, in the presence of (to use her own word) her accuser, Lady Portman, Sir James Clark, and her own maid (whose deposition is now certified upon oath.) Sir Charles Mansfield Clarke:, long known to her &Hilly, was also chosen by my poor sister to attend her.

Lady Flora told her brother, at a personal interview, that "the ex- amination to which she was subjected was conducted with more than ordinary disregard to delicacy and to her feelings."

An extract is given from a statement in Lady Flora's handwriting, which formed part of a case submitted to Sir Villiam Follett and Mr. Talbot- " On the pith of Febniary, sir James Clarke came to me, and asked sae whether I were privately married ; giving, 85 his reason, that my figure had excited the remarks of the ladies of the Palace.' On my emphatic denial, he became excited, urged me ' to confess,' as 'the only thing to save me;' stated his own roan iction to agree with that of the' ladies ;' that it had occurred to hint at the first ; that no one could look 'at me and doubt it ;' and remarks even yet more coarse. " I observed to him, that the swelling from which I had been suffering was very much reduced, and offered him the proof of my dresses. Ile replied, ' Well, I don't think so. You seem to me to grow larger every day ; and sa the ladies think.' He proceeded to say, it was the only supposition which could explain my appearance and state of health ; or else you must have some very bad illness.' I said that was possible, 1 had thought badly of my state of health; but that his supposition was untrue, and perfectly groundless. lie ended by assuring me, ' that nothing but a medical examination could satisfy the ladies of the Palace, so deeply were their suspicions rooted,' and that he must inform Lady Portman, who 'had been his confidante,' of my denial. Ile returned with a reiteration of what he had already said ; and, 1 think, tat I will not he positive, added that it was the more imperative, as the rumour had reached her Majesty. I said, feeling perfectly innocent, 1 should not shrink from any ex.. amino ton, however rigorous, but that I considered it a most indelicate and dis- agreeable procedure, and that 1 would not be hurried into it. I said also that before any thing was determined, it would be requisite for me to know the Dutchess of Kent's pleasure ; and inquired if her Royal Highness had autho- rized these communications to me To my surprise, 1learned that her Royal Highness was still uninformed that the slightest suspicion rested on me.

" It having been notified to me that it was her Majesty's pleasure that I should not appear until my character was cleared by the means suggested, and having obtained the permission of her Royal Ilighoess to submit to it as the most instantaneous mode of refuting the calumny, I sent, on Sunday the Mb, for Sir Charles ;Mansfield Clarke and Sir James Clark, and the examination took place in the presence of my accuser, Lady Portman, and my own maid

" In the evening, Lady Portman came to me, to express her regret for having been the most violent against me. ' She acknowledged that she had several times spoken a great deal to the Queen.on the subject, especially when she lbund it WAS her Majesty's own idea.' She said she was very sorry, but she would have done the sane respecting any one of whom she had the same sus. picion. 1 said, my surprise is, that, knowing my tinnily as she did, she could have entertained those suspicions."

The Marquis is in possession of a deposition given before an Ayrshire Magistrate by his sister's maid, who was present at the examination. She swore-

1 'that while the whole demeanour of Sir Charles Clarke during the painful and humiliating scene was characterized by kindness, the conduct of Sir Jams Clark, as well as that of Lady Portman, Was unnecessarily abrupt, unficting, and indelicate. This deposition 1 withhold, as it contains much that is WHOLLY unfit for general perusal."

It is also stated by the Marquis, that when, after some questions had been put, it was suggested tltut the examination need not proceed any further- " Sir James Clark objected, and stated. that the ladies of the Court would not be satisfied without the strictest examination ; and that, if Lady Flom knew her ow it innocence, she could Lave no reason to oppose the most complete scrutiny."

Letters written by Lady Flora to members of her own family-, and extracts from a diary which she kept, throw additional light on the conduct of the parties to this affair.

THE QUEEN.

" Buckingham Palace, April G. 1539. "It is remarkable, that from that second day, (after Lady Flora's arrival from Scotland,) the 11th of January, to the 23d of Fehuary, the idea, however or by whomsoever suggested * * * * * was so strong in the Queen's mind, that she never opened her lips to me." " With one exception, an inquiry after Lady Forbes's children, her Majesty showed Lady Flora no notice from the 24th of March, the date when Mr. Fitz- gerald's letter was published, until the 9th of June, when her illajesty sent to ask how she was."—slbstracted front Lady Flora's Diary.

THE DETCHESS or KENT.

" She shrunk with horror from the idea of my submitting to the test de- manded: but I urged her, for my sake, for that of my family, and for her own ; for I Mt it right towards her, to allow me to meet the charge in the manner most convincingly and instantly to refute it. I was strong iu inno- cence, and .1 Mt my courage equal to any endurance."

Silt JAMES CLARK.

" Ile (Sir James Clark) began Mitt day to speak to me with some degree of feeling ; but, irritated by my denial, became violent and coarse, and even attempted to browbeat me."

LADY PORTMAN.

"Lady Portman had my forgiveness as a Christian; but I declined ever after seeing or knowing her from her conduct. .‘ 'With regard to the Doteliess of Kent, her Royalllighness had a very warm l ou vre-anon with lier, on every bearing of the transaction; and it was in that eouver,atien Lady- Portman took upon herself to aver, from her experience AS a married woman, that there was no doubt 1 was in the situation they alleged me to be in.

" It is upon that averment that Lady Portman stands committed and con- victed as it slanderer, and nut of that position no ingenuity can take her ; and it was upon that fccling that the ]/tactless declined seeing her, and restricted her explanation of her conduct to a written one, which explanation her Royal tigliness merely acknow hslged, and referred Lady Portman to her Majesty's ad v isers."—[Extrocied sSout Leib rs.] The greater part of the 3luurquis of Hastings's communication to the editor of the Post consists of a detailed account of the steps he tools to discover the originators of the calumny against his sister. He consulted Lord Winchilseit ; who advised him to go at once to Lord Melbourne. Lord Melbourne declared, that lie knew nothing of the matter except from Lady Tavistock ; that he did not believe the rumour himself, and had advised "the ladies of the Court to be quiet." lie gave Lord Hastings his word of honour, "that no one was connected with the business but the ladies of the Court." He recommended Lord Hastings to consult the Duke of Wellington ; but the Duke was not then to be found at Apsley House.

A correspondence between Lord Hastings and Lord Melbourne en- sued. In his first letter, Lord Hastings complains that lie had been kept in town waiting for an interview with the Queen ; and recapitulates the steps he had taken since his arrival, alluding especially to his design of challenging Lord Melbourne.

" I REPEAT, that the whole business has been base and cruel, and reflects dishonour and discredit on all concerned in it, from the highest to the lowest ; and I cannot find words sufficiently strong to convey the sense of my disgust and contempt for the conduct of all who have figured in this business; and though by your assertion, on your word of honour as a gentleman, that the whole thing rests with the ladies of the Court, yet 1 cannot bring myself to think that it has been the deliberate act of leer Majesty, judging more parti- cularly from tine conduct of the Queen since she has discovered the foulness and falseness of the accusation ; but I ascribe it to that baneful influence which surrounds the Throne, and poisons and deadens all the best feelings and dic- tates of human nature. Aud now, my Lord, it may be right for me to state (not only as a duty to my family and myself, but in case misconstruction might hereafter be put upon the line of conduct I have adopted) what I hare done on this occasion. The very moment I heard of it, I posted day and night to London, and, believing that you had been the chief mover in the business, 1 waited upon Lord Winchilsea, and asked him (if such were the case) to call you out. By his advice I called upon you myself, and received from you, on your word of honour as a gentleman, a denial of any participation m it beyond having been sent for by the ladies of the Court. 1 next sought the advice of the Duke of Wellington, Lord Winchilsea being out of town ; and hi,. Grace advised, for the sake of avoiding the painfulness of publicity, that the matter should rest where it now is."

Lord Melbourne regretted that the Marquis's departure should have been delayed ; and an interview with the Queen was promised. It took place on the 28th of February. Her Majesty promised Lordllastings that Lady Flora should be treated with honour and kindness ; but all in- formation " as to who had been the originators of the plot" was denied. Lord Melbourne, however, was exculpated.

Lord Hastings then applied to the Marquis of Tavistock and Lord Portman ; and a long correspondence ensued. Lord Tavistock's let- ters are written in a tone of frank sympathy with the affliction of the calumniated lady and her family, but all that could be obtained of a specific nature was the following statement of Lady Tavistock.

t; When I went to Buckingham Palace, at the cud of January, to attend upon the Queen, I found strong suspicions of an unpleasant nature existing- there with respect to Lady Flora Hastings's state of health. It was considered necessary, for the honour of her Majesty and the character of the Household, that tL,sc suspicions should not be permitted to continue and spread without some step being taken to put a stop to them. Observing the opinion in ques- tion was borne out by appearances, and conceiving that Lady Flom might have been privately married, 1 felt much desire to speak to her at m.o., upon the subi, CI ; but circumstances occurred which prevented my carrying this wish into effect, and rendered it my painful duty to inform the Prime Ai iaister of the opinion that had been unfortunately entertained 1 hope I did ,o in the most delicate and cautious manner, and for this 1 consider myself responsible.

" ANNA 1I.ditiA TA.visTocK.

0 Oakley. 15th March 18:9."

In a letter to Lord Portman, the Marquis of Hastings put the ques- tion plainly—" whether Lady Portman's suspicions were suggested to her, or occurred to herself; and what communication, if any. passed be- tween her Ladyship and the Baroness Lehzen." Lord Poi tman's reply was unsatisfactory ; and the tone of his letters, compared with Lord Taviskek's, is cold and hard, if not coarse. lie furnishes a statement from Lady Portman ; which communicates no new fact, except that her information respecting Lady Flora was not derived from the Baroness Eehzen.

Then followed the Marquis's letter to Lord Melbourne of the 5th of April, formerly published ; and the correspondence between the Dowager Marchioness and Lord Melbourne, which must be fresh in the recol- lection of every reader. The rude manner in which Lord Melbourne addressed the Dowager Marchioness, compelled the Marquis to demand an apology from the Premier. The entire correspondence is published. Lord Melbourne's letters are characteristic : he could not see any thing offensive in the tone or matter of his letters—lie was ready to retract any " expression" which gave offence, but they must be pointed out to hint. Finally, he declared that he had no intention whatever to treat her Ladyship otherwise than with the utmost respect ; and Lord Hastings was satisfied.