The managers of the Washtenaw County Aswciaüon for the improvement of the breed of Horses have perfected their arrangement for the coming show to be held on the grounds of the Wash. County Agricultural Society, in this city, on Friday, Saturday, and Monday, Juljr lst, 2d, and 4;h. Over $600 are offered in premiums, which it is promised will be contested for by sorne of the best horses in the States. The Programme provides for two trots on Friday afternoon, one for a purse of $75, the lest ihree mile heats in five ; the purse to be iirided into three premiums. The other for 1'25,-best two mile heats in three ; to be di'ided into tliree premiums. Saturday there is to be a pacing match for i"5 for single horses, best three heats in flve; ndalike purse of $75 for doublé teams. The first divided into three premiums, and the econd into two. Also first and second premiums for single and matched carriage terses. Momlay, a trotting match for $175 ; best 'hrep in five, in three premiums, single horses. Also a J50 match in two premiums. No entrance fee is to be oharged.. but ten P'f cent will be reserved from the premiums aitarded. The net proceeds of the exhibition are to k'appropriated for the benefit of the Michi!l0 sick and wounded soldiers.