Washington (May 9) Diapatch to ChlOAgo Times. Montgomery Blair has written the following lotter on tho Cincinnati Conveution and tho futura course oi' the Demopratio pavty. It is addressod to a prominent Democrat in Baltimore : Washington, May 7. - We will havo to tako Greelöy or Grant, and we will tobe Greeley, relu.;tantly, of ( ours ', but not the les; cor'ain y, and he will be tho more certain of election becauso tho DemOOrats do ïot wish to embrace him at first. As for their running a candidato. of their own, that woukl bo both disMtrous and disgraceful. They all gave in their adhesión to tho Cincinnati Oonvention, and tho most obstreperous of Groeley's opponents had their cuudidate before that convontion. Voorhees, for Itmplo, was loud in his advoeacy of Jtidge Davis, and tho World was earnest in pressing Adains. Now, there certainly ou,n be no greater departure from principie in supporting Greeley than there was in supportiug Adams, or Davis, or any other radical. Tinao caí be, in fact, no imtive assigned for fehe support of one of theso inon and the rezasal to support either of the otbar?, bn msre persona] preference. Tfais is not stateemanship, Ifc is mero caprice, if not soinet hing woree, whieh men eau indulgu in without tho loss of public confidence. For my own part, I go for thu morement initiated at C'ineinuati to arrest th9 progress of radicaiisra. It is a practioal way of arrasting it. As for running in a straignt Democratie ticket bcttvaen Greeley and Grant, that. is :i dodge that will not be allowed to suceced." That fian be done only on thj soi ill fi(;ll of local politics, where the contest between real aspirante is personal and h:is becöme embitterfd. But tho contest between tho Ilepublicm and Demoorotio parties has always boen a sootional one, one party representiusT tho North and the other thfi South, and in acontc3t of thut obaracter the Kepub lic;m BUecess is assured by the census. ■ It is only by dividing the more nuruerüui North and ;;llying itsolf with the more liberal división that the Démoöraoy representing the fiouth '-an hope for tho recovery of tho right of Belt government for it.s section. The moment that the Democraey shall set up ior itself the North will close its ranks again, and the only effect wouldbe to sacrifice the leaders in the Liberal party who had atteinpted to help is. This would disgrace us, and so help to defeat us, not only now but hereafter. Of courss there will be some honest Democrats, who will not re gard tho subject in this light, and who will prefer to stand by their guns, etc., but tho noisiest follows will be those who are in the pay of the administration. Chandler said recently, I learn on good authority, that thero would be n. straght Democratio ticket, and that ho would giw 125,000 to start it himself. Thero are a good many Democrats of tho Twe I cader ready to tako his mouey and hlp to keep tho statu qno which is profitable to thoso follows who nnd rstana m.inipuhiting claims quietly, and the administration has tbs public purso at its disposal, and understands them and how to make tho most of them. There were over 190 officeholders of them, Grant's cmissaries, in Cincinnati, working for Adams. They were neaily aU from Washington. I oan furnish the namea of about tifty of thera. The strategy of Grant's frienda was to socuro for him the Irish vote by putting Adams on us, and so compénsate foi the losa of tho Liberal Bepublicar. vote, but he failed, and they aro furious. The groat majority of Adams' supporters did not understand it, but tho public mimi ignow thoroughly aroosed, and when this is the case, tli power of purchasable . individuáis and of tho venal prass is , siderable.