From Washington

FROM WASHINGTON.

General HERRAN, the Minister of New-Granada, professes to think he yielded t much to General CASS in the treaty recently signed, settling the questions between his Government and that of the United States. He demanded fifty thousand dollars per annum from the United States to enable New-Granada to keep her treaty agreement to protect the Isthmus transit, urging that the Panama Railroad, though of vast value and importance to the United States, has never brought to the Isthmus itself any of the advantages expected to have accrued therefrom, and such as usually flow from the establishment of a work of this kind. It might be answered that if this be so, it results in great part, from the inefficiency of the Isthmians themselves. Certainly, the road affords them a ready, prompt and comparatively cheap means of getting to the best markets in the world, with tropical products such as the Isthmus is abundantly able to produce. If the people occupying its cheap but fertile lands do not chose to cultivate them, and so get rich off the markets thus opened to them, it is their own fault. Again: It must be remembered that the railroad has not had time yet to work out a tithe of its incidental benefits sufficiently to make them manifest to the superficial observer. As the frontiersman in a forest country has first to clear his land by “felling” the trees and getting out the stumps, ere he can expect to see the best fruits of his enterprise, so the railroad in this case has had to contend with the thriftlessness, ignorance and semi-barbarism of the Isthmians. It has had to do the work of civilization ere it cold begin to develop other and more material influences and results. No one who glances at the gigantic strides with which the new commerce vid the Isthmus is advancing to greatness, can doubt that the country in which and through which it passes, must find extended employment in connection with it, and so reap abundant profits therefrom. Whether the people of New-Granada shall do this business instead of letting it fall into the hands of strangers must depend entirely upon their own energy, enterprise and capacity.

But to return to the treaty, Gen. HERRAN states that he supposed at one time he has secured his $50,000 per annum bonus from the United States, to hire his Government to do what was already its duty by the treaty of 1816. I do not believe he is sincere in his lamentations over his failure in that respect. Surely he must see that an agreement on our part to any such proposition, in the settlement of our peremptory demand for redress of grievances suffered at her hands, would have been degrading to the United States, and have subjected us to the derision of diplomats everywhere. Gen. HERRAN may be assured that he got off very well, in successfully resisting all our demands save that for pecuniary indemnity. He has obtained a Mixed Commission to sit upon the adjustment of undisputed claims of citizens of the United States! – than which he needs no better certificate of his diplomatic skill, -- although even that would scarcely have availed him in this instance, had not Gen. CASS looked perhaps too leniently upon the weakness and imbecility of his Government. If England had been in the place of New-Granada, it may be doubted whether the amiable and excellent Secretary of State would have yielded so much.

The claims of American citizens to be arranged under this treaty amount to over a million of dollars. To adjust them a Commission is to be appointed, of which New-Granada selects one member, and the United States another. If these disagree in any case, it is to be referred to the Prussian Minister at Washington for his decision as umpire. Claimants will be interested in knowing that Baron GIROLT, on whom this delicate duty will fall if occasion arises is universally esteemed as a most excellent and honorable gentlemen, whose decisions are quite sure to depend solely upon the manifest claims of equity and justice. For the payment of fifty per cent. of the awards which may be made, one half the money falling to New Granada from the Panama Railroad Company is appropriated by the treaty. For the remaining fifty per cent., New-Granada will issue her “promises to pay” to the United States Government, the latter accepting them, and thus becoming responsible directly to the claimants, instead of leaving them to depend upon the questionable faith of the foreign Government. If Congress shall indorse the treaty practically, by assuming this responsibility, and paying the claimants without waiting for the maturity of the New-Granadian paper, of course they will get their money promptly, --otherwise it will be a long day before they ever see the second half of their dues securely in hand.

Hon. JOS. L. WHITE, of your City, was here a day or two ago, to look after the interests of the Accessory Transit Company, of Nicaragua, but did not succeed in getting the Administration to espouse the cause of himself and associates. The course of the new Administration in relation to Nicaraguan affairs has been precisely what your columns foreshadowed months ago. The policy in brief has been first, to warn Costa Rica that the United States will not assent to her exercising any right of conquest in Nicaragua, consequent upon her operations against WALKER as an ally of that Republic, so as to close up the Nicaraguan Transit Route; and second, to abstain from every act which should lean in the least towards espousing the cause of either of the contesting claimants to the right to conduct the Transit business upon it. This policy was fully set forth in a letter addressed to WM. CAREY JONES, special agent of the State Department in Costa Rica, evidently intended to be read by him to the Government of that Republic. This fact transpires through the Ministers of other Central American powers, to whom, it seems, copies of the letter were addressed recently by our Government, to notify them clearly of the position assumed by the United States. Whenever a de facto Government in Nicaragua shall make an arrangement definitely settling who is entitled to the franchises of the Transit grant, the United States will undoubtedly make a treaty for its protection, as was done in the case of the Panama Transit: -- but Mr. BUCHANAN will never touch the subject at all until this necessary preliminary step is taken. The fact that England has formally signified that she sustains the doctrine advanced by the United States, is announced by the representatives of Nicaragua as an important guarantee of her territorial rights against Costa Rican encroachment.

While on the subject of foreign relations, let me deny emphatically that Mr. FORSYTH, our Minister at Mexico, has been authorized to offer any money for the purchase of a right of way across the Isthmus of Tehuantepec. Whatever may e done in the future, the Administration is not yet committed to any such measure. When Mr. BUCHANAN, as Secretary of State, authorized the payment of fifteen millions in the Trist Treaty for this right of way, it was unquestionably of vast importance to the United States. But affairs have much changed since that time. In the present advanced condition of American interests upon the Pacific, a Tehuantepec Transit is of little practical value; and the payment of any money whatever by the United States for the right of way, would amount to nothing save the sacrifice of just so much public money, in furtherance of a moon-shine stock speculation, to put a percentage of the sum expended to private pockets Mr. BUCHANAN will hardly risk his high reputation for integrity and common sense in any such scheme.

I learn that the announcement of the removal of D. B. MARTIN, Engineer in Chief of the Navy, was premature. The machinations of those who urged his displacement had nearly succeeded: but Secretary TOUCEY has probably discovered the speculative motives of those who desired Mr. MARTIN’S removal, and is not willing to permit such injustice to a faithful officer, whose only fault was his inflexible determination not to aid rat-trap patentees, or Pennsylvania Coal Companies, in dipping their hands into the Treasury to the public disadvantage. The prevailing impression now is that Mr. MARTIN will remain in his present position if he chooses so to do.

The National Hotel is to be opened again, on or about the 1st November, by Messrs. JONES, CHAMBERLIN & TENNEY, from New-Hampshire. Workmen are now engaged in putting the building in thorough repair. It will be remembered that the entire sewerage system connecting with the building was changed last Spring, and there need be no doubt that the cause of the endemic of last season was thus entirely eradicated. A fact, by the way, to which sufficient attention has not been called, would seem to establish conclusively the theory that the sickness arose from defective sewerage. It is this: that the laborers who were employed, after the hotel was closed, to take up the old sewer connections, and to build a new sewer from the house to the canal, were nearly all taken down with the precise symptoms marking the disease when the endemic was at its height. I heard the statement at the time, but had no opportunity to verify it by inquiry until during my present visit to the Capital.