Mr. Caleb Cushing,--"the Ajax of the Union," as he has lately been styled,--for what reason we know not, unless that Ajax is chiefly known to the public as a personage very much in want of light,--Mr. Caleb Cushing has received an invitation to dine in South Carolina. This extraordinary event, while it amply accounts for the appearance of the comet, must also be held to answer for the publication by Mr. Cushing of a letter almost as long, if not quite so transparent, as the comet's tail. Craytonville is the name of the happy village, already famous as "the place of the nativity" of Mr. Speaker Orr, and hereafter to be a shrine of pilgrimage, as the spot where Mr. Cushing might have gone through the beautiful natural processes of mastication and deglutition, had he chosen. We use this elegant Latinism in deference to Mr. Ex-Commissioner Cushing; for, as he evidently deemed "birth-place" too simple a word for such a complex character as Mr. Orr, we could not think of coupling his own name with so common a proceeding as eating his dinner. It may be sectionalism in us,--but, at the risk of dissolving the Union, we will not yield to any Southern man a larger share of the dictionary (unless it be Webster's) than we give to a gentleman who was born at --we beg pardon, the place of whose nativity was--Newburyport. Mr. Cushing has distinguished himself lately as the preacher-up of a crusade against modern philanthropy; and we do not wonder at it, if the offer of a dinner be so rare as to demand in acknowledgment a letter three columns long. Or perhaps he considered the offer itself as an instance of that insane benevolence which he reprobates, and accordingly punished it with an epistle the reading of which would delay the consummation of the edacious treason till all the meats were cold and the more impatient conspirators driven from the table. Or were those who had invited him _negrophilists_, (to use Mr. Cushing's favorite word,) and therefore deserving of such retribution? Not at all; they were all _leucophilists_, as sincere and warm-hearted as himself. Or perhaps this letter expresses Mr. Cushing's notion of what a proper answer to a dinner-invitation should be. We have no "Complete Letter-Writer" at hand, and consequently cannot compare it with any classic models; but, if we remember rightly, that useful book is not in as many volumes as the Catalogue of the British Museum is to be, and the examples there given must necessarily be denied so sea-serpentine a voluminousness. We suspect that the style is original with the Ex-Brigadier-Attorney-General, but, while we allow it the merit of novelty, we think there are some grave objections to its universal adoption. It would be a great check on hospitality; for, by parity of reason, the invitation should be as tedious as the reply, and a treaty of dinner would take nearly as much time as a treaty of peace. This would be a great damage to the butchers, whose interests