The Resignation Of Gen.

Tn my dispatoh of Friday, I am mrtdtí to wajr, in spettking of the rumora as to tlio causa of Secret ury Casr reMignatiun, "all these rumor areuntrue." It should have been, 'two" of them are iinfruo. The otber - 'Ao refusbl of the President to gond troop to Charleston - was the cause of the witbdrawal ot Gen. Cass from tho Cabinet, as hit letter to Mr. Buchanan proves. I undorstand that the Piosident's roply is in e;i;irso of preparalion, and that it niil be very .vero upon the late Pro2ier. It appcara that Gen. Cass reigned ♦en duya ago, but Mr. Buehanan refused to accept tho rosignation unleas reimon was utteigned. When that portion of tho message, rrfomng to tho want of power in Congres to maka war upon a State, was read by iiuchan:in to Uen. Can?, tho lsiter is represented as taking the President by the hand and thfHlbing hiin for his statesmu'-like viowt. Smco then Secretniy Cass has urged t!.e use of the army and navy to enteren a duo oxecu'io!) of the Federal lawa in South Carolina, and threatenod to reeign if it erenot d.ne. Secretary Flovil joined icsuu, and prornied his reeigontioo it' any forces were ordenjei to (ballestón. In this extreniity Ger). Scott wan again t(l(gnphed for, and cong'ilted by the President. Itappenrs tliat Ciipt. Ándersor, comin nding Fort Jloultrio, first reported to Gen. 8eott, but was referred by the General to tnu Saorutarv of War, aa ho (Gen. Scott) had no orderí to give. On tho Geileral's arrival here, hu insistod on nut baing com)ücated in tho matter at issue betweeu Secretarie Cass nul Floyd,but at tho name lime stated, unequivocally, that ho appioved of ttio viowm uf the latter. Thig decided Mr liuchauac's couTua and Soeretary Cass) tendeid bis resignation. Tho Pienident demandod his reason. Theo have lean comntanieated, and a responso w.ll be given to-raorrow. I undejMtund that G-en. Cass, in his letter, retera topastt hintorv, whon an ndminwtration met t'.io sa:no quticn as it shoti!d be mot, mutaining the constitution and the lawg. Jacküon w&a tlien at the head of nffairs, and Cass was tho Secretary of War. 11e complains that different counsels now pro vai!; and that his voice is no longer regardod. Tho President, I onderstand, wi.'l reply at soine length, refening to sornu of tho factH to whioh I have alluded. The correapondence will be published in a few day. Spcoial Di-patoh to the N. Y. World Washington, Dec. 16. Official accaiiDts of Gen. Cass' withrlrawal say : On tho question of eoereing a State in the Union by military forue, the Preaideat and Gen. Cass are perfectly united in opinión. The diffieuUy aroso from the fact that Cass insisted that the naval und military foroe shguld bo sopt airnediately to Charleston to re r.foreo tho forts in the harbor ; and that the President was of the opinión tbatthere is no necessity for mich n measure in order to secire the forU against attack. This being the Prefiiient's conviution, ha would not anjtinn any niovemant whieh might !o;;d ?( a colusión in the present escited btute of feeiiog in the South. Thegovernment has infonnation that Fort Moultriu is prepared to withstand tlieattack of alarge forse, the general ronovatioQ of the fort and the mouuting of guns having been Ciunpleted. The gun.s are shotted every night. Quite a sharp correspondenee took placo between Gun: Cass and tho Pronulent, whioh, it is beüeved, will bü pubifilicd. Oen. Cass' letter will cortainly be made pubüc. Special Dupatch to tlu S. Y. Trilune. Washington, Deo. 16. General Cass' reia;nation has produced a morj deoidod effect herethan any recent erent, and uarrowed the lincs between the frie.ids and enemies of the Union. Nothing but an extreme case could have induced General Cass ta rotiro at this timo. Flis conduct is Rpprnvod by all partios but the avoweil feoeofísionií-ts. This is testified to by the general manner in which he has been viyited since then.