The evening of Saturday, Aug. 21st, will long be remembered by the _habitues_ of the Opera. From exclusive sources (which have been opened to us at a very considerable expense) we are enabled to communicate--_malheureusement_--that with the close of the _saison de_ 1841, the _corps operatique_ loses one of its most brilliant ornaments. That memorable epocha was chosen by Rubini for making a graceful _conge_ to a fashionable audience, amidst an abundance of tears--shed in the choicest Italian--and showers of _bouquets_. The subjects chosen for representation were _apropos_ in the extreme; all being of a _triste_ character, namely, the _atta terzo_ of "Marino Faliero," the _finale_ of "Lucia di Lammermoor," and the last _parte_ of "La Sonnambula:" these were the chosen vehicles for Rubini's _soiree d'adieu_. As this _tenor primissimo_ has, in a professional _regarde_, disappeared from amongst us--as the last echoes of his _voix magnifique_ have died away--as he has made a final exit from the public _plafond_ to the _coulisses_ of private life--we deem it due to future historians of the Italian Opera _de Londres_, to record our admiration, our opinions, and our _regrets_ for this great _artiste_. Signor Rubini is in stature what might be denominated _juste milieu_; his _taille_ is graceful, his _figure_ pleasing, his eyes full of expression, his hair bushy: his _comport_ upon the stage, when not excited by passion, is full of _verve_ and _brusquerie_, but in passages which the _Maestro_ has marked "_con passione_" nothing can exceed the elegance of his attitudes, and the pleasing dignity of his gestures. After, _par exemple_, the _recitativi_, what a pretty _empressement_ he gave (alas! that we must now speak in the past tense!) to the _tonic_ or _key-note_, by _locking_ his arms in each other over his _poitrine_--by that after expansion of them--that clever _alto_ movement of the toes--that apparent embracing of the _fumes des lampes_--how touching! Then, while the _sinfonia_ of the _andante_ was in progress, how gracefully he turned _son dos_ to the delighted auditors, and made an interesting _promenade au fond_, always contriving to get his finely-arched nose over the _lumieres_ at the precise point of time (we speak in a musical sense) where the word "_voce_" is marked in the score. His pantomime to the _allegri_ was no less captivating; but it was in the _stretta_ that his beauty of action was most exquisitely apparent; there, worked up by an elaborate _crescendo_ (the _motivo_ of which is always, in the Italian school, a simple progression of the diatonic scale), the _furor_ with which this _cantratice_ hurried his hands into the thick clumps of his picturesque _perruque_, and seemed to tear its _cheveux_ out by the roots (without, however, disturbing the celebrated side-parting a single hair)--the vigour with which he beat his breast--his final expansion of arms, elevation of toes, and the impressive _frappe_ of his right foot upon