The Oberlin Slave Rescue Cases. - Three more of the Oberlin slave rescuers have entered the plea of nolo contendre, and been sentenced to $20 fine and costs and 24 hours imprisonment. The affair is still producing great public excitement, and a mass convention of the people is called at Cleveland on the 24th, to express their feelings in relation to it. At a public meeting in Jefferson, the shire town of Ashtabula county, on Saturday night, resolutions were adopted denouncing the fugitive slave law, and pledging the prisoners at Cleveland that if judicial relief was not ultimately afforded “no prison should hold them.” At the suggestion of Mr Giddings the “Order of the Sons of Liberty,” taking name of the revolutionary organization of ’75 in New England, was formed, at the head of a hundred others. Several old line whigs are in the movement. The organization will be extended over the State, and “will be heard from when it is wanted” – the meaning of which is forcible resistance to the fugitive slave law. It needs no prophet to see that the administration, by its determined persecution of the Oberlin people, has done its best to make slave-catching in Ohio impossible for all time to come.