In France and Belgium also the compositions of the coal mine explosives are published, but in Germany, as a rule, only a list of the constituents is given, and sometimes an upper or lower limit for one or more of the principal constituents. Moreover, it is not stated explicitly whether the explosives are intended for use in coal mines or for general blasting purposes. In the United States of America, explosives in tended for use in coal mines are examined by the Bureau of Mines, which, however, has no power to prevent the use of others because regulations on this matter are made by the individual states. If they pass they are placed on the list of Permissible Explosives. The compositions are not published, but the class of composition is stated. Until the second half of the nineteenth century, gunpowder was practically the only explosive used on a considerable scale, and it was employed for all purposes. Consequently it does not fall into any of the classes mentioned, or rather it could be placed in several of them.