By a reference to an extract from a city cotemporary, which will be found printed in another column, it will be seen that the writer sums up the value of the interests in patents for which extensions are solicited by act of Congress, at the enormous sum of f 43,-000,000. We do not consider it an extravagant estimate. Some of the patents specified in the list are the most valuable privileges in the world—more valuable than any gold mine in California—because they have been worked and their capability fully demonstrated. We have no doubt whatever that an extension of the Colt & Goodyear patents for seven years longer would yield a net revenue of twenty-five millions of dollars—a tax which would be wrung oHt of the people's pocket by special legislation.