A Demonstration was held yesterday afternoon at St. Giles's Hall, in connection with the Imperial Association, for the raising of Agricultural and other Prices, "to protest still further against the late unrestricted ability to live on their means enjoyed by the British Middle Classes," and "to take ulterior measures for rendering it more impossible." A large number of members of the Association were assembled, among whom were the Duke of GLUTLAND, the Right Hon. JAMES MOWTHER, Mr. GRUNTZ, Mr. C. W. BRAY, M.P., and others. Mr. FLOWERD MISPENT, M.P., said he was proud to take the chair on such an occasion, and to congratulate the assembly on the immense progress made in the country of the principles they were met to advocate. ("_Hear, hear!_") Their great object had been, by forcing the Government to put a prohibitive tax on all foreign imports whatever, to so stimulate home industries, that while the producer flourished at the expense of the consumer, the latter, representing four-fifths of the nation, was driven to the verge of desperation by a general rise of prices, that he was powerless either to stave off or meet. (_Loud cheers._) He thought that the great bulk of the Middle Classes of the country must, if not already hopelessly ruined, at least have got it pretty hot. (_Laughter._) Take his own case. Owing to the new import duties levied on foreign wool and silk, the tweed suit in which he stood up before them on that platform had been charged to him by his tailor at £37 15s. (_laughter_), while his hat, for the appearance of which he could not say much, had cost him £5 18_s._ 6_d._ (_Renewed laughter._) Such prices as these must tell in the long run on the pocket of that great enemy of national industry, the "Consumer." (_Cheers._) The Chairman then read letters of apology from the Duke of TWICKENHAM, Lord STARCH, and Baron DIMOCK, M.P., who declared their readiness to favour any motion calculated to stimulate a still further rise of prices. Mr. JOLLIS, M.P., wrote in a similar sense, and in a letter expressing regret that he was unable to be present, Lord HAPENCE said:--The brilliant future that is now dawning on the prospects of the British Agricultural Interests must be patent to all. Only yesterday I was charged 18_s._ 6_d._ in a local hotel bill for a small _omelette_, and, on asking for some explanation, was informed by the waiter that since the importation of French eggs had ceased, the market price of those procurable from English poultry had risen to 4_s._ 6_d._ (_cheers_), and they were not to be relied on at that. This is as it should be. Need I say I paid my bill, not only without a murmur, but with positive satisfaction. (_Loud cheers._) * * * * *