The Detroit Weekly Advertiser gives some very interesting information on this subject the result of the patient labors of Dr Houghton and other gentlemen, who have been engaged in developing the riches of this State Michigan contains coal, and in the neighborhood of Sandstone, two hundred and fifty tuns have been raised during the past season The coal is of good quality, and the working is safe and easy The beds outcrop for a hundred miles or more on the Grand river, and from more recent discoveries would seem to extend to the Straits of Mackinaw Quantities have been sold in Jackson county at $3 per tun, and when some system is employed in the mining, it is expected to be much cheaper The State is working a shaft by convict labor in the prison of Jackson Copper occurs frequently in the upper peninsula, and silver has also been found to a considerable extent C8,nnel coal has been discovered in Jackson county which makes a most excellent gas